Cards I'm not thrilled with in your build:
Mizzium Mortars - too low impact. You already have Blasphemous Act and you won't often need to wipe the board.
Hordeling Outburst - Krenko is your best token producer. Use him!
Illusionist's Bracers - it's a bit "win-more." The best uses are Kiki-Jiki and Krenko, but if you're far enough ahead to cast this, equip it, and get an activation, you're probably already winning.
Bravado - better to deal damage by going wide, plus there's no way to recur it in mono-red. Equipment is better.
Captive Flame - you probably won't have enough mana for this to matter, and if you're sac'cing your Goblins to Skirk Prospector to activate this, you're doing it wrong.
Lightning Crafter - I've always found it to be lackluster. 3 damage doesn't kill many things you really care about and you're not going to win by pinging for 3 every turn.
Goblin Razerunners - you're willing to sac' your lands to this thing? Brave soul...
Goblin Snowman - just...why?
Also, if you don't realize - Goblin Tutor is an Unglued card. My playgroup doesn't allow these, but if yours does, it's stupidly broken.
Cards I think should be in your build:
[[Goblin Lackey]] (and also [[Warren Instigator]]) - look at that adorable face, then go sit in the corner for ten minutes in shame for not auto-including him.
[[Shared Animosity]] - move it from your "Maybeboard" to your "Under-no-circumstaces-would-I-not-play-this" board.
[[Gempalm Incinerator]] - better than most regular removal spells. It can't be answered with regular counterspells if you desperately need to remove something. It doesn't go to the face, but I find that I almost always win with Goblin token beats.
[[Gamble]] - helps you tutor for win-condition artifacts. You can even cast it on turn one to go and get Sol Ring (this is almost always the reason you'll cast it turn one).
[[Chaos Warp]] - this is your "I need to answer this thing immediately and I don't care what else they get, because it can't be worse than that" button. Having Instant-speed permanent removal in red is a rare and beautiful thing.
[[Stoneforge Masterwork]] - this is basically a better, reusable Bravado.
Any effects you can get stapled to a Goblin are great because you can tutor for them. For example:
Artifact hate - [[Tuktuk Scrapper]], [[Goblin Tinkerer]], [[Goblin Vandal]], and [[Goblin Welder]]. I actually run all four, as I've never been sorry to draw one.
Nonbasic land hate - [[Goblin Ruinblaster]].
Graveyard hate - nope, no Goblin for this. [[Tormod's Crypt]] will do.
Other considerations:
[[Foundry Street Denizen]] - powerful with Krenko.
[[City of Shadows]] or [[Mercadian Bazaar]] - storage lands are good if your Commander gets hated on a lot. Not good if there's lots of land destruction in your meta.
Extra ways to push through damage - [[Hellrider]], [[Contested War Zone]], [[Signal Pest]], [[Haze of Rage]], [[Breath of Fury]] are fun ones.
[[Battle Hymn]] - second Brightstone Ritual.