BPA is just "don't screw up." No one complains that Romanov wasn't BPA anymore, though there was some griping at the time. The first 5 to 10 picks are more and more reliable every year, so it's pretty risky to reach with really early picks, but once you are into the teens you have to hope your scouts know more than the media, and that you know the player that will help your team. Even with that there are years like the Slaf pick where there was no consensus at the time, and not much now. Cooley looks good, as does Nazar, but the habs didn't really have space for another small forward, though either could have replaced Newhook. Slaf has been up and down.
Taking KK when he wasn't really in the discussion was a reach, compounded by bad development. McCarron was a reach because they could probably have taken him a round or two later. Taking one of 5 guys ranked in the teens at 16 or 17 is not a reach, unless you are passing up Caufield. I doubt you need to worry much about BPA or anything else by the end of the second round because any player who makes it will have developed so much that he is unrecognizable from draft day.
The habs have often failed in the draft chasing big players, since the last cup, and been successful with small guys who dropped. They need to find a few good big players, and they can't really play another small D, but they shouldn't pass on an elite small forward.