lopackuub

goblin grappler combined with ib can kill any 4 toughness creature your opponent controls

dont' have so many one ofs. also mogg war marshal will give you three creatures to sac and voracious dragon will go great with all the goblin sacs.

llanowar reborn can get you some +1/+1 counters, spire tracer is hard to block. gruul war chant makes your creatures harder to block and gives them a boost. madcap skills enchants , pumps, and makes a creature harder to block.

mogg war marshal can get you three creatures to devour and can combo with voracious dragon.

Don't have so many one of cards and maybe use vorel of the hull clade or gilder bairn to double your level up counters and maybe use tezzerets gambit.

izzet staticaster
goblin sharpshooter
Zhur-Taa Druid
Deathbringer Thoctar

Mirko Vosk, Mind Drinker - hes a vampire that mills.
Anowon, the Ruin Sage - would force opponents to sacrifice creatures every turn
Balustrade Spy - another vampire that mills.
Szadek, Lord of Secrets - also a vampire that mills.

mogg war marshal gives you 3 total goblins for the same price as krenko's command. ib halfheart, goblin tactician would get rid of any blockers. breath of fury would give you a ton of attack phases if you used goblin tunneler to make sure the creature with it wasn't blocked.
goblin warstrike could be used instead of banefire if you just concentrate on getting lots of goblins on the field.

Gaea's Blessing will make sure you don't mill yourself

maybe only put in one copy of each creature and use the extra card space for other cards that would support your combo

varchild's war riders, although its off color

also Orcish lumberjack could help with mana problems in the first few turns while keeping with the theme of land sacrificing

Goblin Razerunners

Breath of Fury + Boggart mob + Goblin Chieftain( or any other card granting goblins haste) + Goblin Tunneler ( or any other way to make a creature unblockable) =
Infinite Goblins and Infinite Attack Phases

use green and add some time of needs to make sure you draw kazuul, also look at Varchild's War-Riders.

you could use quest for renewal to solve your problem of tapping for mana and tapping your blockers. since your lands will be creatures and you can activate the quest just by tapping for mana.

cards like:
Life and Limb
living lands
living plane
natural affinity
natural emergence
nature's revolt

can make lands into creatures

and Dryad arbor is a land creature

you can make sure your opponent plays lots of creatures with varchild's war-riders, and forbiden orchard

Jinxed choker

bazaar trader and jinxed choker

jinxed choker

quest for the gemblades
ascetism
mayeal's aria