Lemoon you want every piece of the game radically changed. The range isn't changing and all we want is to balance incendiary the way it is, and to make it useful in the guns it has potential in like the gat, lumber, and light carro. Reducing damage to 30% while increasing rof, fire chance, and doubling clip would completely change its use in current guns, and in my opinion make it near useless.
The question is what is the best and easiest change that pleases people. My vote is affecting dps because the fire chance is good at 40% total (could be slightly boosted) and the -30% range is perfect. The only thing holding it back is that dps is way too low, and radical changes are unnecessary when there's a simple fix. I'd like to see incendiary have use on guns like banshee or hades, and we want to hear new ideas that balance, not remake, the game.
My point with greased vs incendiary flame is that greased already starts enough fires and I consider it a good upper limit. I don't think incendiary should significantly outperform greased but I have no qualms if it ends up being super greased flamethrower. I don't think it would be at all balanced but I don't care enough to dispute.