-snip-
Hm..that just made me think of something that'd be pretty interesting for stats for like a Rocket Launcher or something.
Something like "The Blood Pact". -25 health on fire, 50% of damage done converted to HP, 15% reduced projectile speed. It'd increase the survivability of the Soldier...if they can aim. I was thinking something similar for a scout primary but I couldn't think of a way it wouldn't be either OP or pointless, because unlike the the Rocket Launcher, it's a hitscan, so for example, a Scout v Scout battle would end with you winning 100% of the time if it had proportionally lower damage on fire, or it'd have too much and be useless unless you have 100% perfect accuracy, or it'd just have to be a downgraded scattergun with this effect which sounds even worse.
Edit: Actually I think this would work pretty nicely for a Spy primary: -25 hp on fire, 80% damage converted to health, 50% slower reload speed, no random crits. It could even possibly let you stack up a bit of Overheal.