Shooting sync was completely fixed for on foot fights. Vehicles are still attached to the lag shooting/pitting as of RC1. Script doesn't detect if you hit something with a melee weapon, a throwable or a missile which is a great flaw but I hope they fix this in the upcoming RC's. I also hope they add some detection for aimbotters/joypad users.
Current callbacks allow for a serverside track of damage without having to use highly repeating timers/big checks and it is possible to create serverside tracked HP/Armour for an anticheat really easily; with the new callbacks working ammo anticheats can be put in effect too.