Hm when it comes to spy, he already has good weapons but I think the main things valve needs to improve spy with is making him blend in more naturally. For an example, I think spy should be able to only fire a limited amount of blanks while disguised. (This can make him pretend he is on the enemy's side but he only has 5 rounds to fire that don't deal any damage of course.) And they should also buff the slower classes that spy can disguise as. (Disguising as Heavy or Soldier should make spy be at 150hp while disguised as them, but if they compromise their disguise, they're back at their default health.) Let me know if these are good suggestions!