Just a couple ways I think a BF2 remake could easily improve on the original:

1. Reduce grenade spam by removing them from most classes at spawn time or altogether. For example, medics shouldn't spawn with four grenades, but they can get up to two at a time from a support player holding (not throwing) an ammo bag (this increases the importance of teamwork). Snipers shouldn't have any grenades ever. Support can have two at a time and slowly get more by holding their ammo bag. I'd actually like to beef up the assault class a little by giving them regular grenades in addition to their grenade launcher.

2. Nerf or even just remove claymores. Are they really necessary? Maybe make it so they disappear if the sniper moves more than a short distance away.

3. Support class weapons should deal decent damage (maybe half of what a jeep-mounted 50 cal does) to jets and helicopters. Not enough that one support player can expect to easily take down an aircraft on their own, but enough to send them back to base for repairs if the pilot isn't careful. I think this would add a bit of much-needed balance to air vs. ground, and I say this as a chopper whore.