I like that.

faster huntman charge while midair, greater jump height and reduced health. (this idea is rough because I cant be bothered to do percentages)

Just like in Parkour Fortress, he can wall jump.

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+75% charge speed on sniper (and huntsman) while jumping or in the air.
-50% charge speed while on the ground.
+10% reload time
+20% weapon change time.
+20% jump height
+20% air movement speed (like air straifing)
maybe a wall jump if this isn't too OP.
+20% movement speed.
maybe lower health or extra projectile damage vulnerability if the stats make the weapon OP.

There are a lot of +20% 's in these stats because this seems like an amount which would make a difference but not enough to be too noticable and annoying, you wouldn't notice +10% reload time if you weren't paying attention but it would make a large difference. These stats could probably be changed by 5 or 10 percent either way since I haven't done too much research into all the original stats (like normal jump height, reload speed, weapon change speed, charge speed and movement speed) and some are probably not too well thought out by me.

maybe sniper can shoot and move normal speed (no slowdown when charging bow) and maybe faster speed

Lets you run on water and you don't get wet from any sources