boas are very docile, and can generally take a small adult mouse from birth (might be why he's taking so long to eat a pinky, and why he's being grumpy). if a boa doesn't have an absolutely great feeding response, there's something wrong with it.

boas almost always look ready to strike, it's just the way they lay. you got bit because he was hungry, not because he's mean :p.

try a small live mouse next time. i think you'll be surprised.