Just took a look at your pictures – looks like you have a lot of sanding in your future.
From the pictures, the wood looks sound and I would expect it to respond well to refinishing but it is very weathered and I really think it should be removed to seal it on all sides and then re-bedded (along with the other hardware). I know it's a PITA but you'll get better results, the actual refinishing will be easier off the boat and you can refit it, nice and watertight, over your new paint.
If the non-slip is painted on (looks like it) and sound, you might be able to scuff it up and paint on some kiwi grip or similar. But that crazed paint definitely needs to go so that you have a sound surface to paint. I'm no expert on paining fiberglass so I’ll leave that for others to comment on but, in case you haven’t found them already, here’s a little light reading.
Good luck and keep us updated.
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