What is the best way to prolong gelcoat life?

I have a friend that says that waxing, polishing is only good for the
pilot, does almost nothing for the gelcoat.

I really don't know much about this issue.
Would it make sense to cut a bit off like .002 every once in a while to
stop/prevent any crazing? Then wax it?

Does Gelcoat off gas over time and then start going bad?

Seeing how very little time most ships are out in the sun, a lot of them
look rough. Sailboats sit outside 24/7 and can look good for many years.
Whats up? Should I be parking my LS3a in a Marina?

Do nothing or try and work on the gelcoat to attempt to get the longest
life out of it; or something in between?

If Gelcoat does off gas, and kind of dries out and cracks,would it make
sense during the winter lay up to cover the gelcoat with a coat of wax, to
seal it, and then buff it off come spring?