What’s the best way to fix these and what’s the easiest way?

I don't know what is the best or easiest (because I usually do things the hard way), but I drill it larger than the thread diameter and inject thickened epoxy in with a tube on a syringe. Mask around it to make clean up easier.

Unless I'm in the wrong context, then I can't help with that.

Get a bigger screw??

In fiberglass/gel? Like resurrected said if you can’t simply fit a bigger screw, drill the hole out, fill with epoxy then drill and tap.

Some glass guy named Dave had me take a tooth pick with epoxy on it and plug hole. Let it dry and break off clean on surface. Screw is tight and hasn't moved in 5 years on my rub rail.

Small plastic sheet rock anchor in the over sized hole works well

Ha, that was my dads solution. But it seems to me the plastic is too soft to bite into fiberglass and it doesn’t always stay when I need to remove the screw again

I like the tooth pick method. Make sure you use genuine bamboo toothpicks, bamboo does not absorb moisture.

RR

So one of my step kids showed me a trick he saw on youtube and used to fix his guitar.......backing soda and super glue. It turns rock hard almost instantly and can be sanded. You could fill the hole with some backing soda and squirt some super glue on it...then drill a new hole and ready to go. I would probably do it in small stages as i dont know how deep a hole the superglue woudl be able to fill in one shot.
Also i was thinking....what if one was to take some fiberglass house insulation less the paper backing ofcourse....(if they didnt have any fiberglass matt on hand) and mix it up with some epoxy and stuff it into the hole.....should work just the same i would guess.

That sounds cool ^^^^

Anyone, How about an epoxy gel (ie:thickened):