Okay, I have no MM neck experience, but I can answer several of the questions.
1) Without seeing the neck I can't be sure, but this sounds like the neck finish on most Fenders. Usually less finish is better than more, but you can strip it and put on your own finish, heavy if you like, but: You will need to strip and finish the whole neck to get it to look very even. If you just do the back it will be hard to hide the section where it transisions to the original. Id leave it, but if you do strip: 2) I'd but a few cans of gloss laquer. Available many places, just be aware of it's fumes and thus potential to explode if sparked. Check out the various titorials and threads.
3) Where did you come to the conclusion that you couldn't stain maple? It is one of the easiest and most commonly stained woods. On to 4), it sounds like you want a polyurethane finish, which can be sprayed on or brushed on. It will be hard, thick and fairly glossy, but it can be a pain sanding thick coats down. Good luck and get some photos.