That fin business sounds a little like fin rot. Please look for the section in the quicklinks which deal with that.

Now if he doesn't look like that is a problem, you still have those white spots. If the white spots are big, it could be Ick or Ichthyophthirius. If the fish are showing really tiny spots, but so many of them that they form a velvety sheen than the disease could be velvet or Oodinium. More recently is it classified in the genus Amlyodinium or Piscinoodinium.

Googled images, so you can make comparisons, could include the following.

http://www.aquaculture.bz/fish-disease/Velvet-Disease.html

http://dieterott.de/krank/salz.html

http://www.elacuarista.com/secciones/enferme4_parasito.htm
images of both Ichthyophthirius and  Oodinium

http://eric.petfish.net/ich.htm

There is a lot of advice to be found in the Guppylog Quicklinks under Ick and velvet.

By the way,
http://home.xta.com/fishdoctor/page6.html

suggests that seemingly healthy fish could carry it dormant in their skin. The disease would flare up if tank conditions declined. I just mentioned, as a part of a comment to savednloved's recent log submission, that I was puzzled as to how it got into one of my tanks last year. That may partly explain how it "appeared" my fishroom.

If your poor male has two maladies, treat the "spots" first in the tank, with the others because they have now been exposed to the illness too, while making water changes and then see if the finrot still needs to be dealt with. I'm sorry you are faced with this. You have done your best to quarantine that male. Sometimes things just don't work the way we hoped they would.