Liza - I'm sure you will get lots of different opinions here is my .02
I'd be more than a little concerned. I think sometimes we can get caught up in the psychology of past relationships and blah, blah, blah....sure they may have some influence. Such as, those of us that have been with an A won't go down that path again maybe to the extent of not being with someone who drinks at all.
However, his projection of telling you how YOU should be feeling, and pointing out to YOU the downsides of dating him is huge red flags to me. You aren't that far from having dated a year. The "L" word at the point isn't inappropriate or rushed. I suppose he could be passive aggressive in a round about way and trying to clarify how you feel about his situation, but seems you haven't given him any reason to be concerned.
He sounds to me like a guy who doesn't want to get remarried and perhaps thinks this is where it is heading. If he doesn't have any relationship fears why is he bringing up things that one should be fearful about?? Like your girlfriend dumping you because she is fed up with dealing with your young kids as her own have moved on???
Something isn't adding up, at least not to me.