While dwarf angels are a bit hardier then large angels they still require more established tank then yours is at the moment. Flame angels seem to be hit or miss IMHO. They seem to border the dwarf/large hardieness line. The Alk seems on the high side too so I wonder if it added stres to the fish.
BTW my tank is running at 81-82 and has hit 85-86 with no fish or coral lost. Did loose a few snails when it hit that high. I have 2 clowns, a Vlamingii Tang, a BG Chromis, a six line, and a sunrise dottyback.