Due to that (his size), there is little reason for concern that Bourque hasn't lit the world on fire in his first professional season.
I don't find his size a concern, but considering he's playing a 3rd/4th line role typically, I'm not sure how he's supposed to score with the linemates he typically has. He has been on the PP of late though with the callups, so hopefully something clicks there for him.
One thing he does do though, is hit anything that moves. Reminds me of Antti Pihlstrom in that aspect.