As for Crysis 3, Crytek still hasn't released a mod SDK. I have no idea why (even with working on DLC, it shouldn't take this long for mod sdk) and we better hope it isn't locked down like Crysis 2 so that we (the community) can fix Crytek's constant failure at trying to make their own anti-cheat.
The next time Crytek releases a game, just wait a while to see how the reviews are and how many hackers have infested the game before buying it.