He is a risk but he also has medical experience.
I'd definitely keep Daryl, Glenn, Maggie and Rick (even though he has a few screws loose at the moment). Michonne seems to mostly care about herself, though I don't blame her for being cautious. Merle is a loose canon that could go off any second, I wouldn't keep him around. Carl is growing up pretty well, and Hershels other daughter is fairly helpful.
I'd be scared to have a baby around though o.0 One crying fit and the zombies would be all over you. Would definitely have to be VERY careful.