Nostalrius Begins - Quality wow vanilla realm (1.12)

Ive been looking around for a bit and i am unable to find if the imp's firebolt damage scales with my spellpower/int/stam..

other than the improved imp and improved firebolt, how can the imp put out more damage...

Warlock & Hunter pets don't scale at all with their master's stats before BC. You can find that in 2.0 patch notes, or some patch near that when it changed on retail. The only way to increase your Imp's damage output, aside from the talents you've mentioned and debuffs on the target, is the BWL Warlock Trinket (The Black Book), which increases you pet's damage & armor by 100% on use.