disclaimer: the numbers are just placeholders and estimates, they are not set in stone.

increase pyro's health to 225. pyro can't really fight back against any class if he is popped up in the air during a solo encounter against an opponent, especially soldier. Instead of depending on a reflect or miracle to save him from this situation, he can now survive three rockets, three meatshots, etc., giving him more of a fighting chance.

Change flamethrower to function like a lightning gun (from quake) but has falloff.
long range - 14 dmg per however the lightning gun functions
mid range - 17 dmg
close range - 22 dmg

give pyro grenades for increased mobility and to attack enemies
grenade jumping be something like this.
https://www.youtube.com/watch?v=MgbGfIyA318
https://wiki.teamfortress.com/wiki/Concussion_Grenade_(Classic)
except no concussion, instead it releases smoke that blocks the enemy's view, it does not explode (it won't be giant cloud, just think of a reasonable size that the smoke should cover). if you right click, it triggers the grenade into a fire-mode and instead of releasing just smoke, it explodes dealing explosion dmg and rains a small condensed shower of fire like a mini-napalm.

the grenade is the loose cannon. the longer you hold down primary fire, the more the fuse gets closer to having the grenade explode.
explosion dmg deals 80-120 dmg?!

increase afterburn to 4 dmg. well pyro's broken now xd.

nerf/buff if pyro is moving in the direction in which he's shooting, he'll receive a 20% decrease in movement. in reverse, he'll receive a 20% increase in movement if he is moving in the opposite direction he's shooting. and yes pyro is male confirmed.

yes i also posted this on reddit. criticize and tear up my ideas apart because i don't know how to comp.