They will grow to be up to 12" long (female) (thus requiring a 120 gallon tank). And yes, it does hurt if they bite you when they are bigger. Crush has broken the skin on my fingers before and she's only 6". But, that was when I first got her. She doesn't bite as hard anymore, just kinda nips to let you know she's serious.
I think it's good to take them outside for some fresh air now and then. I'll leave mine in the back all afternoon sometimes. As far as watching tv with you, that might just be causing the turt some undue stress which could make it more aggressive. I doubt the turte enjoys tv. Probably loves the garden tho

. How long do you leave it in he garden at a time?
They're not really social creatures who like to be handled and pet, especially as babies. When they get bigger they may become more social. Mine have been. How long have you had it?