I feel your pain. Everything in post.
#5 is my favorite, probably why I also take allopurinol. It's just natural to cherish things that ain't good for you!
Looks like it was there to deflect rain from the bilge vents. Maybe you can find a bit of resistant lumber, cut it to fit, stain a nice color and polyurethane. I like a little wood on a boat.
Yep just bring it in the house. If I were in the thiefin mood I would take the whole rig. LOL.
seriously tho a cable and good lock is about the best you can do.
That will work if you cover it with the keel guard. @Scott Danforth can give you the process using gel and cabosil but it's costly unless you have areas that need to match.