I suggest you to do a complete uninstall. DO NOT use ingame uninstaller, use and download the freeware RevoUninstaller and uninstall all the civ components from that program. It will clean the HD and registry for every trace civ will otherwise leave on you HD.
After that install the game, make sure to apply latest vanilla patch before upgrading to warlord and latest warlord patch before installing BTS. Apply latest BTS patch and then install BUFFY. Forget other mods, at least for now, and tell me if it works.