I'm going to try and keep a running list of suggestions in this thread. If you don't see your suggestion here, please post in this thread. Try to keep posts to suggestions and not discussing whether they are good or not.

Player / Classes

• Limit the number of classes allowed per squad / per team
• Revived player has decreased health (i.e. 50%)
• Change increasing spawn rate (i.e. 20 second initial + 2 second * # of deaths)
• Decrease damage done by AT missiles (light vehicles / armor destroyed too fast now)
• Increase overall stamina
  • Increase cost of stamina per jump
• Allow instant respawn at UCBs or Main CPs (if missing UCB)
• Decrease the range for the player tag to be visible to make players look before they shoot
  • Allow sniper weapon to see tags when using scope
  • Only display tags of squad members
• Give Spec Ops six c4, but two triggers (i.e. one trigger for each of three c4)
• Allow snipers to call for artillery strikes
• Add claymores to Spec Ops class
• Decrease stamina as health decreases
• Do not allow two jumps within a given amount of time (i.e. 2 seconds)
• Add player bleed (i.e. if less than 50% health, player slowly loses health)
• Death by bomber or artillery does not increase player spawn

Weapons

• Arming delay with grenade launchers
• Do not allow firing when jumping
• Do not allow reloading when jumping
• Add a delay to firing when changing from standing to prone (and vise versa) position
• Increased weapon accuracy
  • Sniper rifle one shot one kill
• Use recoil instead of firing cone
• Increase support SAW accuracy when prone, decrease accuracy otherwise
• Adjust weapon ammo amount to be more "realistic"
• Remove crosshairs
• Decrease sniper class ammo amount
• Decrease weapon accuracy as health decreases
• Create a stinger kit (for AT class)

Vehicles (Land / Water)

• Decrease spawn time for small / light vehicles & watercraft but leave the abandoned damage value low

Aircraft

• Decrease spawn time to equal that of all vehicles
• Decrease payload
• Decrease splash damage
• Make bombs have a recycle time similar to that of the TV guided missile.
• Remove transport chopper ammo
• Decrease blackhawk ammo
• Increase overheat rate for blackhawk weapons

Assets

• Allow one asset to be used every X minutes
• Allow only X number of uses per round
• Disable artillery during last X minutes of round (to avoid arillery strike win)
• Only allow COs to accept artillery requests
  • Disable SL artillery request from map view
• Decrease UAV radius
• Decrease UAV active time
• Decrease number of artillery on a map
• Do not allow supply drops to repair assets or bridges

Capture Points

• Do not neutralize immediately
• Do not allow defending team to spawn if assaulting team within radius
• Do not allow flag to move if assaulting team in a vehicle
• Increase rate at which flag returns to initial position if assaulting team not within radius
• Increase flag capture radius (i.e. to 5 meters)

Other

• Add a logging / tracking feature for in-house statistics
• Increase the time before dead bodies disappear
• Increase repair time for assets & objects (bridges) so they aren't usable right away

Notes

• Some features would be great on their own, but the combined feature causes problems. For example, the fact that it takes a player at least 30 seconds to spawn should be enough to stop defenders from spawing too fast... but adding in that you can't spawn on a CP while occupied might not necessary.
• To keep aircraft in the air, but not always engaged, decrease the spawn time but increase the time to reload / repair.