As for liking the aggression of your fish; some surgeons like the cutting involved in surgery. Jadefoodog, I've actually seen less aggression in a crowded tank. Too many fish around to focus on any individual for long. I've also found that I can feed some of the aggression away. It means more maintenance for me but sometimes works. Full bellies gives them one less thing to fight about. On the subject of live food, live black worms have been known to carry parasites. I don't feed anything live unless I grow it myself.
Mark
Mark