I see they still haven't fixed the nationality problem... I mean, it's not only lazy as hell but downright racist in some cases. I'm sure there are some Baltic NHL players who wonder why they can only draft Russian-sounding players from their countries. Implicit social commentary much?
The weight/height problem stems from the fact that each player grows at a fixed rate until they're 20 (I think?) and add a few pounds over the course of their careers. Usually players can add anywhere from 30 to 60 pounds from the day they're drafted until their prime but EA hasn't bothered/figured a way to simulate players "bulking up" in preparation for the NHL and over the course of their careers. So you end up drafting tons of big players from the beginning which will serve to increase the average size, but once they're in their mid-late 20's they'll be more or less on par with real life.
The players are too tall, though, and it's a carry over from previous versions. In my NHL 12 file like half of my players are 6' 4" or taller, and there are teams who don't have anyone smaller than 6' in their roster.