conservatism is important in reef keeping IMO. If you want to keep healthy corals, you can't just load up on fish, especially fish that get large. I don't know if any of you have ever seen a full size vlamingi relieve itself, but does "milkshake" ring any bells?
As far as the fish schooling, they all do in some manner during the day, but also break off to roam as well. Teh heps are very prone to hanging out together, as are the yellow tangs and purple tang.
The heps are most interesting because they actually play games, and encourage other fish to join in. Their most popular game is toss-the-bubble, in which one will gulp air from the surface, swim down and about, and release the air. Then the other tangs will try to suck the bubbles back in, and release as well.
This goes on for hours at a time and I have seen multiple other tangs as well as wrasses join in the fun. It's an odd sight to be sure, that the casual observer might not notice until I point it out, but then it is amazing to watch.
I am sure many of you have noticed fish riding the currents as well, and my fish really seem to do this as a sport.