A flame angel will be fine in a 55G. Tangs, ABSOLUTELY NOT. There is not one tang out there that belongs in anything less than 75G and even that is a stretch. As a general rule, tangs do not belong in a tank less than 90G.
Get the damsels out, they will cause problems later and will probably kill off your stock list, and then turn to your hands. They're evil little fish.
A nice stock list for a 55G with what you have listed would be:
Flame Angel
Wrasse (or two)
Clown (or a pair)
and then some small other fish such as a goby and/or blenny
Firefish?
Don't overstock.