Yes. You either install all updates or none. Yes. I'm sure it wouldn't update as often if you never checked, but I'm pretty sure after about 6 months you'd get a forced update. I just started doing this with a few computers, so, just a guess, it'll probably be a year before I have a good answer. I've got a laptop in storage I could set up like this with something like 1709 and just leave it online and see what it does, so I might do that. Edit: Really the whole point of this is to do manual updates when convenient and not so much to never update again.