Grenades! Yes! I <3 grenades.Add back in grenades

Id remove the pyro. They always catch me in my disguise!
Remove hats.
Redo a couple class packs, but limit each class to only having 1 replacement for each slot.
Add in a rank up system similar to CoD, but it's purely for show. No unlocks from it.
i like rank up system with no items or perks from it the perk system is what made me quit COD but maybe you could get a rank "badge" you could wear like the badges they have
My vote would be to return the air-blast for the Pyro back to the way it used to be, it's too easy to just spam m2 & get reflect kills now.Although it is fun catching someone on fire & juggling them into a corner until they die.
Make everything available to everyone, hats and all.
Remove hats
Remove drop system
Remove trading (not necessary when hats and drops are gone)
Remove polycount
Remove engy update
Remove pyro compression blast nerf/mini crits on reflects
Humm, I think I could think up more, but it would be difficult!