I don't know from your post exactly how long your tank has been up and cycled, but it sounds like you are stocking REALLY fast. A rule of thumb (even though I don't like those) is one fish per month after the conclusion of the cycle. Your biofilter is established after the cycle, but the bacteria population has to grow over time to match the bioload. Too much bioload too fast and the natural filtration can't keep up with waste management.
Dwarf angelfish are very often a problem with some corals (nipping) and with more than one of their type in a tank (fighting to the death)... and by their type, I mean two dwarf angels, not two of the same species. Not guaranteed, but pretty common.
Not trying to sound preachy, but going off of the impression I get reading this, it sounds like you aren't researching thoroughly with the stocklist.
Like I said, I don't mean to come off wrong, and these choices are by no means guaranteed trouble, but be careful. I would like to see you succeed without big problems.