I don't know whether the stones that gave The Ghost his power recovered, weren't they left lifeless at the end of the special....?
I don't like the idea of actual Superheroes active in the Doctor Who universe, but this was a one-off special and despite my misgivings I ended up rather liking it. It does suffer from some of the trends that were coming in at that time from the BBCs fixation with gender politics, but as a concept and design The Ghost and his debt to superhero comicbooks was well handled I thought.
From what I remember, The Ghost did still keep his superpowers at the end, as he was going to look like marry his lois and become a dad!
Just thought that he was a good parody of Superman, and would like him to be revisited in the future!