Hopefully someone more experienced with treating fish like Stunreef will chime in, but I think at this point the most important thing is to feed feed feed.
You need to get the fish's immune system up and as strong as possible first so that he has the strength to tolerate what ever medications you're adding to the tank.
Once your confident the fish is getting enough nutrition, I would then worry about taking care of fin and scale issues.
But Im fairly certain that through feeding appropriate diet like Nori, and New Life Spectrum Pellets Thera A+ formula, a little mysis the fin issues will take care of them self and hopefully will be in a better situation to battle any potential ich issues.
Test the params of the tank and keep us posted!