How curved should the end of the front targa latch be? The part that can be adjusted with the two nuts.

Also I have some separation where the latch screws onto the fiberglass and the screws are not holding.

Has anyone ever used fiberglass filler or gorilla glue?

As far as anchoring the screws fill with epoxy and coat the screws with silicone. Screw it all the way in and let it sit. You should be able to screw it back out, but just leave it in.