Can ceramic tile be put over existing fiberglass edge of swimming pool?

Answer 1

yes

However the edge must be very stable - ie must NOT flex if you stand on it. If it IS thick enough there are special products to do this sort of thing.

for example check out this site:

http://www.fiberglassswimmingpooltiling.com/kits.html

Answer 2

yes you can put tile over almost anything. The most important item would be that the mastic / or adhesive would be required to be a water proof, (non affected) type, and dry with a certain amount of flexibility. The best type is a silicone based adhesive that will remain a little pliable. There can be no water during the adhesion process though, and you will not be able to use a normal grout. They make grout simulated materials that are similar to silicone as well, but without sheen and therefore give a finished look.