Danno,

Try putting marine carpet on the ramps - that should make some difference. Keel wear is a pretty standard thing and usually it is repaired by filling any holes and then putting an extra layer of fiberglass or kevlar on the keel. You can usually by a 2" wide roll of fiberglass (or kevlar) that works really well in this application.

Your mast cap is not a comptip - that is a plastic top mast section used on some Hobies and is about 3 or 4 feet long.

I'm not sure exactly what the top of your mast looks like but it sounds like you do need to remove the cap, reseal, and reinstall it. I'm guessing you have a cast aluminum cap that is recessed to fit inside the mast and is riveted in place? If so, just drill out the rivet heads with an oversized drill bit (1/4") (being carefull not to drill out any mast material). Punch the rivets into the mast, remove the cap, apply bunches of sealant (3m 5200), re-rivet the cap in place...alumnimum rivets would be fine in that application - monel as well.