DedWards

Destructive Revelry mainbord? O.o I've always seen it as a Sideboard card...

Smash to Smithereens does similar. It doesn't need green and does 1 more damage, but can't target enchantments...

Strangleroot Geist is an awesome creature with undying. Yes, it's 2 green, but it also has haste, making it very aggressive.
A set of Terramorphic Expanse or Evolving Wilds will help a lot with the mana fixing.

Yes, it does trigger normal storm, you're still casting each Myr Retriever, even if no mana is spent. Grapeshot is the perfect red card to go with it, if I had the money for the duals that'll be needed...

Nicely done :P

Gitaxian Probe and Manamorphose? Effectively 'free' draw spells that add to the storm count.

Brave the Elements saves the tokens from mass burn.

More dead bodies for Bitter Ordeal, in case I can't combo with 2 Retrievers.

Junk Diver would be nice as Retrievers 5 and 6, but again, it's not Modern legal. Also, costing 3 makes it not come in for free off 1 Heartless Summoning.

If I owned Beseech the Queen,I'd definitely use it in majority of my black decks.

Grapeshot and Selhoff Occultist are cool options. If I where to splash, Grapeshot would definitely be the one I splash for as it costs 2.

As for Ashnod's Altar and Tendrils of Agony, sadly, they're not Modern legal.

Problem with your deck: Suture Priest and Blood Seeker only make your opponents lose life if the creatures enter under their control, not yours. Impact Tremors only triggers for creatures entering your under your control, not for the opponent nor your allies.

So, if you where to play Alliance of Arms, the opponent can choose to pay 0 and receive no creatures, thus not losing any life from Suture Priest and Blood Seeker.

Too bad Sensei's Divining Top is banned in Modern, it would've been awesome in here.

A few Door of Destinies wouldn't hurt either

Heritage Druid - allows you to tap elves with summoning sickness for mana, draws you a card if Gilt-leaf Archdruid is out and all for 1 mana :p

Mardu Woe-Reaper is cool, but Mardu Strike Leader is a rare, thus going against the limit I set for myself.
I kind of like Aven Skirmisher, it's a 1 drop with flying. Combat evasion is very nice.

I don't know.... It costs 4 mana....

Not to mention the infinite damage from the Blasting Station itself.

Thinking about it, concentrating on the damage from Blasting Station, you could use any creature that returns itself to your library, this makes it possible to use a cheaper (mana cost) creature for the combo, making the combo go off sooner. (Vigor comes to mind)

A few cards you may want to consider:
Supply // Demand - the Supply half produces x Saprolings for {X}{W}{G}
Scatter the Seeds - 3 Saprolings for 5 convoke-able mana
Selesnya Evangel - churns out 1 Saproling a turn
Pallid Mycoderm - a white 'thallid' with an ability to boost all Saprolings and Fungi power and toughness.

I've been playing since around 2003 and there's a lot of cards I still don't know. When designing decks, I often use this website:

http://gatherer.wizards.com/

It is Wizards database of every MtG card ever made.

Peer Through Depths can help dig for any of you instants or sorceries.

A few cards that may interest you:

Lashwrithe - makes your big creatures even bigger :p
Wayfarer's Bauble - best colourless land search card as it puts the land onto the battlefield, not into your hand.
Tendrils of Corruption - a kill spell that gains you life.
Corrupt - slightly more expensive than Tendrils of Corruption, but can target players, so it can be a game finisher.
Ghoulcaller's Chant - returns 1 creature or 2 zombie creatures from the graveyard to your hand. Korlash is a zombie. (more Grandeur)
Revive the Fallen - returns 1 creature from the graveyard to your hand and has a chance to return itself to your hand. (more Grandeur)
Mutilate - board wipe. Any creature you equip with Lashwrithe will survive.