Easy Off is basically lye. It will soften fiberglass
and discolor it, unless you are careful about getting it off prompty and then acid-washing (vinegar) and rinsing to counteract the alkali. Lye is a great classic paint and varnish
remover--if it doesn't eat too much.
Any auto body shop supply should carry 3M and other brand name products. The vinyl can be removed by heating
it (heat gun on low, or a very hot hair dryer) and/or using solvents (naptha and the like, or special adhesive
removers that work a little faster and cleaner) to release the glue, which is similar to rubber cement.
The paint is a bit more difficult, there are special "rubber" grinding wheels from 3M and others that will erase pinstriping paint without hurting the gelcoat--but without knowing what paint was used, you may have to buff/compound/dissolve that if the wheels don't work.