ComangliaNah, other classes just need to be made better.
Demo Buffs that would be cool
-revert sticky nerf (or at least remove the whole rampup bs)
-remove tumble and spin from projectiles similar to how the loch-n-load works
-fix the sticky detonation delay (might not be easy but should definitely happen)
Soldier Buffs that would be cool
-I really like the idea of making the soldier take gunboats self-damage all the time, and just removing gunboats, might be to much of a buff but would be interesting at the very least.
All the other classes need various little fixes or a near complete redo (looking at you pyro), but I doubt any of them would be as effective as scout, but would definitely make them better/less of a pain to play and play against.
I think just increasing soldier's movement speed to match demoman speed would probably be enough for soldier
as much fun as these theoretical are, this is not how valve balances the game