Muktol

I mean no offense, but you might want to read http://www.mtgvault.com/muktol/decks/how-to-build-a-deck/
Short version: 90 cards is way to much for a deck to run smooth and stable

Greetings
Muktol

*like*
I would use "Rune Snag" instead of "Mana Leak" as it will prove more useful if the game takes longer.
You also could add some searchlands to activate "Hedron Crab"'s ability more often, depending on your budget take a look at "Evolving Wilds" or "Scalding Tarn"/ "Misty Rainforest"/ etc. ("Scalding Tarn" could also enable you to play the 'Entering' side of "Breaking/ Entering" if you add a single mountain)

Greetings
Muktol

Your "How to play" description seems to be slightly outdated as you mention "Bonesplitter" which neither is in your deck nor in your sideboard. As for the damage you calculate, you need 8 cards until turn 4 without playing any lands, so that might just be some miscalculation.

I would use "Etched Champion" as finisher, "Bonesplitter" instead of "Isochron Scepter" and "Dispatch" instead of "Path to Exile".
"Darksteel Citadel" might also be interesting for this deck

Greetings
Muktol

*like*
24 lands seem a little bit on the high-side, maybe try to reduce to 22 or 20. I would use the free slots for 2 additional "Vampire Nocturnus" and maybe some more removal or carddraw.
You could also add some searchlands (e.g. "Evolving Wilds" for budget or "Marsh Flats" for non-budget) to increase the chance that "Bloodghast" will come back, and to thin out the lands you will draw later on.

Greetings
Muktol

Some suggestions, based on my monoR burn deck (http://www.mtgvault.com/muktol/decks/monor-burn/)
I would change from "Hell's Thunder" to "Vexing Devil" ({R}; 4/4; When Vexing Devil enters the battlefield, any opponent may have it deal 4 damage to him or her. If a player does, sacrifice Vexing Devil) and give "Keldon Marauders" ({1}{R}; 2/2; Vanishing 2; When Keldon Marauders comes into play or leaves play, it deals 1 damage to target player) a try (maybe instead of "Spark Elemental") or sideboard it and use against fast, creature heavy, decks (e.g. Infect, Tokens or Enchantment)
Also "Shock" could be replaced with "Lava Spike" ({R}; Lava Spike deals 3 damage to target player)

Some further suggestions:
Browbeat ({2}{R}; Any player may have Browbeat deal 5 damage to him or her. If no one does, target player draws three cards), Searing Blaze ({R}{R}; Searing Blaze deals 1 damage to target creature and 1 damage to it's controller. Morbid - If a creature died this turn, it deals 3 damage instead), Skullcrack ({1}{R}; Players can't gain life this turn. Damage can't be prevented this turn. Skullcrack deals 3 damage to target player), Smash to Smithereens (Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller)
Vexing Shusher ({R/G}{R/G}; 2/2; Vexing Shusher can't be countered; {R/G}: Target spell can't be countered by spells or abilities)

Greetings
Muktol

Well some points before we can start working on this one:
Here is a text I wrote concerning general deckbuilding, maybe this may help you a little bit: http://www.mtgvault.com/muktol/decks/how-to-build-a-deck/

How do you want to beat your opponent, which cardpool can be used, and what budget do you have in mind?
(Modern would be back to the 8th edition, standard only back to Return to Ravnica)

Greetings
Muktol

*like*
I think here are a lot more people willing to help others than it may look like. The Problem is, there is no real platform on which you can ask for help on a specific deck, you rely on pure luck, "decks" like this, or someone taking a look and deciding to give advice. It would be a lot easier if the people would tag their decks properly, so that the willing helpers can find them more easy.
This deck will someday vanish, if it's not supported by enough likes and comments, and then everything starts from the beginning.

I dislike "Foundry Street Denizen" because he has no evasion of any sort (Flying, Trample, and so on). So a simple 1/1 token can block your X/1 Goblin, prevent all damage and kill him.

*like*
Personally I would change from "Foundry Street Denizen" to "Goblin Wardriver" or "Warren Instigator".
If you want another removal try "Searing Blaze" instead of "Burst Lightning".
Greetings
Muktol

I would remove "Adaptive Automaton" to add a 4th "Blade of the Bloodchief" and a 4th "Curse of Stalked Prey".
"Rakish Heir" then can be changed to some more effective beater like "Bloodghast"
As for your other spells, I would cut 2-4 removals to add some carddraw like "Sign in Blood" or "Read the Bones"
Last, I would add some standard-lands to this deck. If someone pulls out a "Blood Moon" (All non-Basic Lands become Mountains) you will have problems.

Greetings
Muktol

Less creatures mean more pump for the remaining ones. Bloodrush is a nice thing but far from being a real effective pump. Also it can only be applied to attacking creatures, so if your opponent removes one before you attack you can do nothing against it.
I also would try to add some protection for your key creature.

Some suggestions, based on my own monoG Infect deck (http://www.mtgvault.com/muktol/decks/monog-infect/)
Bonesplitter ({1}; {1} to equip; Equipped creature gets +2/+0)
Ichorclaw Myr ({2}; 1/1; Infect; Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn), Signal Pest ({1}; 0/1; Battle cry, Signal Pest can't be blocked except by creatures with flying or reach), Blight Mamba ({1}{G}; 1/1; Infect; {1}{G}: Regenerate Blight Mamba)
Rancor ({G}; Enchant creature Enchanted creature gets +2/+0 and gains trample. When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand), Wild Defiance ({2}{G}; Whenever a creature you control becomes the target of an instant or sorcery spell, that creature gets +3/+3 until end of turn)
Evolution Charm ({1}{G}; Choose one: Search your library for a basic land card, reveal it, put it into your hand, then shuffle your library; or return target creature card from your graveyard to your hand; or target creature gains flying until end of turn), Mutagenic Growth ({PG} ({PG} can be paid with either {G} or 2 life.); Target creature gets +2/+2 until end of turn), Ranger's Guile ({G}; Target creature you control gets +1/+1 and gains hexproof until end of turn), Vines of Vastwood ({G}; Kicker {G}; Target creature gets hexproof until end of turn, if the kicker costs where paid it also gets +4/+4)

Greetings
Muktol

I would remove "Markov Blademaster", "Madcap Skills" and "Vampiric Fury" to add 4 "Vampire Nocturnus", 4 "Read the Bones" and 4 additional removalspells like "Dismember", "Go for the throat", "Tragic Slip", and so on.

Greetings
Muktol

I mean no offense, but you might want to read "http://www.mtgvault.com/muktol/decks/how-to-build-a-deck/"
Short version, you are using way to many different creatures, and way to many cards in your deck.
If you want to play with a 100 card deck, try commander ;)

Greetings
Muktol

I would change from "Elite Inquisitor" to "Kazandu Blademaster".
Furthermore I would replace "Fiend Hunter" with "Oblivion Ring" because not every deck runs enchantment-removal.

My own monoW human deck: http://www.mtgvault.com/muktol/decks/monow-tribal-human-wheeny/

Greetings
Muktol

I would put the "Blood Artist"/ "Killing Wave" plan into your sideboard, because not every deck you're going after will be a swarm-deck like goblins. The same thing is true for "Blood Seeker". You could also try to reduce the number of "Captivating Vampire" by 1. and add e.g. "Vampire Nocturnus" .

Some suggestions, based on my R/B vampire deck (http://www.mtgvault.com/muktol/decks/rb-tribal-vampire/)
Vampire Nocturnus ({1}{B}{B}{B}; 3/3; Play with the top card of your library revealed; As long as the top card of your library is black, Vampire Nocturnus and other Vampire creatures you control get +2/+1 and have flying), Bloodghast ({B}{B}; 2/1; Bloodghast can't block; Bloodghast has haste as long as an opponent has 10 or less life; Landfall: Whenever a land enters the battlefield under your control, you may return Bloodghast from your graveyard to the battlefield)
Terminate ([R}{B}; Destroy target creature. It can't be regenerated), Go for the Throat ({1}{B}; Destroy target nonartifact creature), Read the Bones ({2}{B}; Scry 2, then draw two cards. You lose 2 life)

Greetings
Muktol

Most of my "normal" decks are out of the budget for sure. But pauper is a great (and cheap) format, so here are my pauper goblins:
http://www.mtgvault.com/muktol/decks/br-pauper-goblins-2/

I would change from 4 "Flames of the Blood Hand" to 2-3 "Browbeat" and 1 additional "Shard Volley" and/ or "Magma Jet"
"Vexing Devil" might also be an option instead of "Goblin Guide"

I you're going to play on tournaments then I would also switch 4-8 lands for "Arid Mesa" / "Scalding Tarn"

I you're up against many non-basic land decks then I would choose "Blood Moon" for my sideboard

Greetings
Muktol

Some suggestions, based on my monoB vampire deck (http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/)
Blade of the Bloodchief ({1}; Equip{1}; Whenever a creature is put into a graveyard from the battlefield, put a +1/+1 counter on equipped creature. If equipped creature is a Vampire, put two +1/+1 counters on it instead.),
Mimic Vat ({3}; Imprint - Whenever a nontoken creature is put into a graveyard from the battlefield, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard. {3}, {T}: Put a token onto the battlefield that's a copy of the exiled card. It gains haste. Exile it at the beginning of the next end step),
Bloodghast ({B}{B}; 2/1; Bloodghast can't block; Bloodghast has haste as long as an opponent has 10 or less life; Landfall - Whenever a land enters the battlefield under your control, you may return Bloodghast from your graveyard to the battlefield), Kalastria Highborn ({B}{B}; 2/2; Whenever Kalastria Highborn or another Vampire you control is put into a graveyard from the battlefield, you may pay {B}. If you do, target player loses 2 life and you gain 2 life), Vampire Hexmage ({B}{B}; 2/1; First strike; Sacrifice Vampire Hexmage: Remove all counters from target permanent), Viscera Seer ({B}; 1/1; Sacrifice a creature: Scry 1)
Dismember ({1}{PB}{PB; ({PB} can be paid with either {B} or 2 life.) Target creature gets -5/-5 until end of turn), Tragic Slip ({B}; Target creature gets -1/-1 until end of turn. Morbid -- That creature gets -13/-13 until end of turn instead if a creature died this turn)

Is there any reason why you are using the same cards, but from different editions?

Greetings
Muktol

I would remove "Devil's Play" for 2 additional "Magma Jet", 1 "Grim Lavamancer" and 1 "Mountain"

Greetings
Muktol