I want to make a deck where it's possible to win with Garbage Fire. This requires 3 things...

A way to make Garbage Fire actually deal non-zero damage:
Akki Lavarunner
Embermaw Hellion
Pyromancer's Guantlet
Pyromancer's Swath
Sulfiric Vapors
The Flame of Keld

A way to turn that 1 or 2 damage into lethal:
Angrath's Marauders
Bitter Feud
Curse of Bloodletting
Dictate of the Twin Gods
Firek Servant
Furnace of Rath
Gisela, Blade of Goldnight (probably the commander of the deck)
Goblin Goliath
Insult // Injury
Quest for Pure Flame

A way to turn that damage on to a player:
Boros Reckoner
Mogg Maniac
Repercussion
Spitemare
Stuffy Doll
Truefire Captain
Also Arcbond and Coalhauler Swine but that's risky...

Now I am trying to find other silly spells to kill people with. I want spells that normally deal very little damage... or ideally can't do damage at all in a normal Commander game(not sure if any exist except Garbage Fire unless I build a deck without artifacts or some other restriction)
So far I am thinking:
Gut Shot
Needle Drop
Zap

Not quite "spells that do very little damage", but a bunch of silly overcosted spells for you:

Ember Shot, Liquid Fire, Structural Collapse, Kamahl's Sledge, potentially Volcanic Vision, Boulderfall, and of course my personal favorite overcosted card: Into the Maw of Hell

EDIT: Also, the errata on Liquid Fire is the weirdest thing ever. I thought the point of errata was to make what the card does more clear, not less.

Also I have a question about replacement effects. Who chooses the order of the multiple effects that modify a "source" of damage, the controller of the source or the controller of the cards with the effects (in APNAP order)?

Sorry for your Garbage Fire plan:





So the player or controller of the permanent receiving the damage would choose the order.

Ah well that's unfortunate... thanks for the clarification though!

Wow... you're not wrong. I believe that's because of the rule that affects other "distributed as you choose" spells that divide among any number of targets - the rules say that to be a "target", you have to assign at least one damage (to prevent something like using Flames of the Firebrand and Cowardice to simulate Evacuation). But that rule would break Liquid Fire if you tried to assign all the damage to the player, because it has "target creature" and that's it, so you'd be unable to have a target creature and assign 5 to its controller.