adhering teak to fiberglass
Oh, I forgot to address a concern re; applying the teak directly to the hull.
Probably not a good idea. Hulls have a tendency to sweat due to temperature changes and if the hull is not insulated to prevent this what you mau end up with is water stained wood, mildew, fungus farms and nasty smells emanating from behind the wood. Also it would be a real bear to get the wood to bend and hold the bent shape to the hull long enough for the glue to kick off. I think you are better off finding a way to put in "furring strips", insulating, and then screw mounting the teak.
What kind of teak are you planning on using, and what is your source?