Muktol

looking good *like*

Nevertheless, some suggestions, based on my monoB vampire deck (http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/)
"Blade of the Bloodchief"
"Bloodghast" (Especially in combination with searchlands like "Evolving Wilds" or "Verdant Catacombs")
"Kalastria Highborn"...2 lifepoint means 1/10th of your opponents total life
"Vampire Hexmage"...at least sideboard material against planeswalkers
"Dismember"...big brother of "Disfigure", can be played with phyrexian mana
"Tragic Slip"...indestructible gods? well not any longer with this spell

Greetings
Muktol

The thing I personally dislike on "Door of Destinies" is that it comes into play and does...nothing. If you don't manage to successfully cast some spells of your tribe it's a dead card. "Coat of Arms" may help your opponent, but that depends on the decks you're going after. If you play in an enviroment that uses many tribal decks, then something else may be better. If your opponents use whatever is available, they might not benefit from it like you will.

Jace is a very good mill card, but as you explained, you want to focus on your vampires (beatdown) and only run mill to keep pressure on your opponents and as distraction (at last that is what I understood). So the only thing Jace does here is buy you time, one to two rounds, depending on the situation.

As for some further cards, try to do some testgames (I use Magic Workstation for this, though you can only play against the same deck in the unregistred version).

It does. So basically you want a vampire beatdown commander deck, with a little mill 'splashed' in.

Then you could think about removing some of the following cards:
"Ashiok, Nightmare Weaver", "Jace, Memory Adept"
"The Chain Veil", "Glaring Spotlight", "Door of Destinies" (Replace with e.g. "Coat of Arms")
"Falkenrath Exterminator", "Jin-Gitaxias, Core Augur", "Nemesis of Reason", "Urabrask the Hidden", "Wrexial, the Risen Deep"
"Curse of the Bloody Tome", "Death Denied", "Cruel Ultimatum", "Glimpse the Unthinkable", "Paranoid Delusions"

I also would recommend to do some testgames and see which cards work and which don't, or which you have in your hand, but can't play, and so on.

A little deck description would help us to help you. Especially in commander it's not that easy to look over 100 (or more in this case) cards and instantly know what the builder had in mind.

There are e.g. several ways to mill your opponent: Stay defensive and use spells, aggressive creatures like "Mirko Vosk, Mind Drinker", use "Phenax, God of Decept" and high toughness creatures, and so on. Also it's makes a big difference if you want to play this deck in multiplayer games or just one on one.

Greetings
Muktol

Personally I don't like "Door of Destinies" because it comes into play and does...nothing. If you don't manage to play goblin spells (and doubling goblins with Krenko doesn't count towards this) then it's a dead card. Could be replaced with "Konda's Banner" or e.g. "Obelisk of Urd"
"Goblin Rabblemaster" is also a card that I personally dislike, because sometimes you have to sit still and wait, but this guy here forces you to attack.
"Goblin Wizard" depends on your mana-curve. If you focus on low-mana creatures then it shouldn't be needed.
"Reckless One": From what I experienced while playing with my goblin deck is that if you manage to get Krenko and some tokens out then it's GG for your opponent, and all those 'power and toughness equal number of goblins' creatures are pure overkill. I still have one or two of those in my deck though.
"Goblin Goon": Cheap 6/6 without any further abilities, thus can easily be blocked by a 1/1 and all it's damage will vanish
"Goblin Grappler"

Greetings
Muktol

I would remove 10-16 vampires to add some support spells (carddraw, removal, equipment, and so on) and 2-4 more lands, depending on your new mana-curve.

Maybe you can take some ideas from the vampire onslaught event deck released by wizards (http://archive.wizards.com/Magic/magazine/article.aspx?x=mtg/daily/arcana/766) or from a revision I did for myself (http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/)

Greetings
Muktol

*like*
Some suggestions, based on my own monoR Krenko commander deck (http://www.mtgvault.com/muktol/decks/edh-krenko-mob-boss/)
Untap artifacts: Illusionist's Bracers, Magewright's Stone, Thousand-Year Elixir
Mass-pump artifacts: Konda's Banner
Creatures: Bloodmark Mentor, Caterwauling Boggart, Goblin Assassin
Instants/ Sorcerys: Massive Raid, Mob Justice, Goblin War Strike

*like*
Some suggestions, based on my own monoR Krenko commander deck (http://www.mtgvault.com/muktol/decks/edh-krenko-mob-boss/)
Bloodmark Mentor, Arms Dealer, Furystoke Giant
Magewright's Stone, Illusionist's Bracers, Thousand-Year Elixir, Konda's Banner
Shared Animosity

I would remove some of the weak creatures (e.g. "Skirk Marauder" or "Goblin Balloon Brigade") and adds some more mass-pump (e.g. "Coat of Arms", "Konda's Banner") or artifacts with tap/untap or copy abilitys (e.g. "Magewright's Stone", "Illusionist's Bracers")
Also some protection like hexproof for Krenko can be useful. From my experience, if your opponent can't get rid of Krenko, or has a lot of mass-removal, than its game over for him.

Greetings
Muktol

Techpriest? For the glory of our Imperator? ;)

Some suggestions, based on my own monoR goblin Commander deck (http://www.mtgvault.com/muktol/decks/edh-krenko-mob-boss/)
45 lands seams to be on the high side, I would reduce it to 40-38.
I also would add some cards that help to pump your goblin tokens. "Goblin Shrine", "Quest for the Goblin Lord", "Shared Animosity", "Coat of Arms" or "Konda's Banner" are cards that I use in my deck
"Blood Moon" can be pretty bad news for your opponents, especially if the play a multicolour deck
As for the creatures, "Goblin Assassin", "Moggcatcher" and "Skirk Prospector" are cards that I really love.

Greetings
Muktol

If it would be my deck, I would reduce the number of mana acceleration/ ramp artifacts and add some more creatures instead.

Some suggestions, based on my own monoR Krenko commander deck (http://www.mtgvault.com/muktol/decks/edh-krenko-mob-boss/)
Artifacts: Illusionist's Bracers (Copy activated ability), Infiltration Lens (carddraw or damage), Konda's Banner (Mass pump), Magewright's Stone (Untap a creature with {T} in it's cost)

Creatures: Bloodmark Mentor (First strike for your creatures), Caterwauling Boggart (Goblins can only be blocked by two or more creatures), Furystoke Giant (Finisher), Goblin Assassin (Mass removal, tough I wouldn't use him before you have Krenko and some tokens on the field), Goblin Bushwhacker (Mass pump for one turn), Goblin Lookout (Mass pump via sacrificing mountains), Goblin Piledriver (Get's +2/+0 for each other attacking goblin), Goblin Wardriver (Battle Cry)

Enchantment: Quest for the Goblin Lord (Mass pump)
Instant/ Sorcery: Massive Raid (Deals damage equal to the number of creatures you control), Goblin War Strike (Deals damage equal to the number of goblins you control), Mob Justice (Deals damage equal to the number of creatures you control)
Land: Nykthos, Shrine to Nyx

Greetings
Muktol

First: It's rather difficult to search through collections as there is no way to sort them here on mtgvault by means of color and so on. It's hard enough to look over a commander deck, and that are only 70-80 different cards that should fit together. I can give it a try, but I will promise nothing.
Second: Do you want to play this deck only with friends, and do your friends also use a limited pool of cards? If not, you could take a look at some cheap cards your local trader/ gamestore might have, or you could also print them as proxy's.

To be honest, I would remove the black part from this deck. If you want to stick with the current color-combination then I would add some more dual-/ or searchlands to stable your manabase and/ or some carddraw.

You are also mixing strategy's and cards that normally belong more into a sideboard here, e.g. what use does "Elixir of Immortality" have in your mainboard?

As for your current cardchoices: I would replace "Door of Destinies" with "Coat of Arms" or "Shared Animosity" as both cards do something immediately after they hit the board (when you attack, that is) and don't need further spells to activate them.
If you want to finish with "Crusader of Odric" then I would play him 3-4 times and make sure that he get's to your opponent. Equipment with trample, flying or unblockable would be my choice in this case as you can use it again and don't loose it completely, like enchantments. "Whispersilk Cloak" would be a good example as it provides the equipped creature with protection (nor only from your opponents spells and abilities but also from yours, that's the drawback on this card) and 'unblockable'.

Basically after you already did some games, see which cards you didn't like or couldn't in your games, and try to find something better/ different for them.

Greetings
Muktol

What about Jeska, Warrior Adept ?

Greetings
Muktol

Here are some suggestions, based on my own monoR goblin commander deck (http://www.mtgvault.com/muktol/decks/edh-krenko-mob-boss/)
Arms Dealer ...point removal against mobs, loves to eat one of your tokens for it.
Bloodmark Mentor ...first strike for all your red creatures, does the same job as Legion Loyalist but without battailion..but also without the trample
Caterwauling Boggart ...your attackers can only be blocked by two or more creatures
Furystoke Giant ...tap your token army to finish an opponent without attacking. Thanks to persist he can be used twice
Goblin Assassin
Goblin Sharpshooter ...your opponent only controls weak 1/1's but many of them? Well not for long with this guy
Goblin Warchief ...lowers the costs of all your goblin spells by {1} and provides haste
Goblin Wardriver ...battlecry
Skirk Prospector ...if you feel that you have to many tokens and to few mana
Blood Moon ...if you go after decks with many non-basic lands
Quest for the Goblin Lord ...bring 5 goblins (e.g. tokens) in the game: All your gobos get +2/+0
Shared Animosity
Coat of Arms
Dangerous Wager ...carddraw
Massive Raid ...shoot damage equal to the number of creatures you control
Goblin War Strike ...see above
Mob Justice ...see above above ;)

Greetings
Muktol

What about "Pariah"?

Greetings
Muktol

"Griselbrand" is banned for commander
http://archive.wizards.com/Magic/tcg/resources.aspx?x=magic/rules/100cardsingleton-commander

The problem I see with "Precursor Golem" on the field is that your opponent only needs a single removal spell, and all your golems are gone. And you have only 3 spells which help to protect your creatures (2x "Refresh" and 1x "Shelter")
The cantrip "Bandage" or counterspell "Hindering Light" might increase the chances for your golems, otherwise I would increase the number of "Shelter" to 3 or 4

Greetings
Muktol

Mill zombies where added in the Innistrad block (like "Geralf's Mindcrusher") and some of them where used in standard builts, simply because there where no better cards available at that time (e.g. "Wight of Precinct Six")
If you want to use zombie sin a mill deck, built an extra deck that focuses on them, but don't mix them. Standard used them (nearly) only because they didn't have access to the top mill spells and needed themselfs to buy some time, in other words, add some defenders.
The advantage of having a creatureless deck is, that your opponent removalspells are dead hand cards, so adding creatures to a creatureless deck...not so good in my opinion.

"Glimpse the Unthinkable" costs arround 20-25, the key-cards to such...specialised...decks are often rather expensive. And "Snapcaster Mage" is good enough that he is used in legacy decks, witch explains his price.
You could also take a look at
http://www.mtgvault.com/muktol/decks/ub-standard-mill/ , a standard legal (M13, Innistrad, M14 and Return to Ravnica) U/B milldeck wich features rather many creatures and uses some removals instead of hardcore-mill. Or
http://www.mtgvault.com/muktol/decks/monou-mill/ which is a monoU milldeck built around "Sanity Grinding". Of course monoU will never be as strong as U/B...