First, KAC cannot prevent users from uploading and downloading files. SourceMod plugins can't do advanced hooking of the engine.
Second, get D-FENS.
http://forums.alliedmods.net/showthread.php?t=109453
Third, I'd recommend using KAC 1.2.0.
Also, the TKills error is well known about and is listed in the Known Issues topic. TKills exists due to problems in earlier versions of Sockets (before 3.0.0 Alpha).