There is no accounting for taste and YMMV, but I really prefer satin on necks, at least on the back of the neck. I wet sand the fingerboard (on maple necks) and the headstock, and then polish with Meguires. I don't polish the back of the neck. I sand it flat with 320 to 400, and then rub it well with a Scotch Brite maroon or gray pad. No wet sanding, which, as you say, would defeat the purpose. You can get a very good gloss from a satin finish if you polish, and this is great on headstocks. But the back of the neck feels faster if you don't.

Some people use the method that you mention, where you use gloss until the final coats then use satin on top. I think the reason is that the glossier the finish the better it tends to level. The flatter the finish the less it tends to level. So, the thinking goes, for a level satin finsh, start with gloss and end with satin. I have done that once, and it worked reasonably well. With the rest of my necks I have just used satin. I don't notice much difference in the way it sands out, and there is no risk that you'll sand all the way through the satin layer.

You can sand gloss back to satin, that's true. I have a bass with a gloss neck, and I keep a 3x5 piece of gray Scotch Brite pad with it so that I can periodically scuff the neck. Such a small amount of finish comes off that you don't need to worry about sanding through, and it definitely improves the feel...temporarily. After a little playing it tends to gloss back up, and you need to repeat the process.