Interesting, because to me, defensive rebounding is definitely part of defense. You need to close out a defensive possession with a rebound to keep the other team from scoring. Obviously I wouldn't consider offensive rebounding a part of defense, but defense rebounding is just as much a part of defense as field goal defense, to me. What good is forcing a missed shot if you don't get the rebound?
This is true, but overall, the point of defense is to keep the other team from scoring points. (Well, also stuff like igniting your own team's offense with steals, etc). We were great at blocking shots last year, for instance, but I think some of that has to be tempered by the fact that we were so terrible rebounding the ball defensively. I don't think those two were unrelated; Fab frequently took himself out of rebounding position to go for blocks. So it's definitely a credit to the team this year that we can still get as many blocks as we do but still do decent work on the defensive glass.
There is one thing I remember thinking about last year or the year before, with regard to defensive efficiency, and I'm not sure if it could be tracked or not. But say you have two teams that have the same defensive efficiency; they each allow 1 point per possession or whatever. If there is one team that does that with say 15 steals per game, and another team that does it with 5 steals per game, wouldn't you consider the team with the more steals to be better? Reason I say that is because defense doesn't exist in a vacuum; you can turn defense into offense. So I'm assuming, for the sake of my argument, that the team with 15 steals is probably getting more transition opportunities and easy buckets than the team with the five steals. That doesn't really have much to do with what you said, but I have been thinking about it. The fact that we were 17th in defensive efficiency last year, but also second in blocks and 5th in steals, might mean that realistically our defense did more to help the team win than the 16th ranked defense, which was New Mexico.