Actually, as scary as it sounds, your kitteh sounds perfectly normal :3
Both my kitties have loved to play fetch, my present kitteh does have a sock fetish and also goes after ankles (and anything else moving :D), and the present kitteh also has a MAJOR fetish towards bags (to the point she will sleep in a bag or climb in any bags available :D).
Either this is normal (especially for older breeds like Egyptian Maus and Maine Coons) or we all have weird kitties :3
Re Sparta going NOM NOM NOM:
The best cures I've found involve Bitter Apple (for stuff) or wearing kitty out (for trying to use you as a particularly interesting chew toy). Also, a lot of cats have ticklist tummies :3
Re the chattery noise--a lot of cats do that right before they go for prey (it's thought they're imitating biting into the neck of prey animals or trying to call them).
Good luck with you and Sparta (it sounds like he's a really special kitty and lucky to have found you :3)