a few things. first things first, windows 10, unless you're on 3rd gen intel or older, you will not have second screen ability. this also applies if you're on NVIDIA graphics card. if you have light perception, I honestly feel sorry for you guys in advanced. sadly, can't comment on AMD.
secondly, if you're on win10 home, unless you tweek it, no group policy, therefore, no control over drivers and updates.
yes, as long as your hardware was registered on the windows 10 activation server, whether that be a clean install or otherwise, your OEM KEY will be detected. even if you wipe off every single partition that ever existed from your hard drive.
now, let me add some rather contrivertial opinion into the mix. don't use classic start menu. if you ever have to use a PC without it, or if the program is ever killed off, you may struggle using the regular menu. I understand that people don't like it, but please, learn how to use it, to avoid from being in the deep water.
I'm currently on windows 7 and 8.1 respectively, have 2 world war surviver laptops over here, and I'm honestly not sure what I will do in 2020. putting the win7 to 10 isn't an option, the fan can't keep the CPU cool enough, and we're talking of CPU temperatures in the 90s.
disabling UAC. I'd consider disabling it a bad idea, period. if one is using a standard account, I guess this isn't really a big issue. pressing alt-y periodically won't hurt anyone, and I'd rather do that, than some random bullshit getting installed. even if I'm installing something, that thing could then install something else in the background. that's just all sorts of no no.
as for NVDA and JAWS reading the UAC prompt, NVDA is faster, but both screen readers read it equally. I'm an NVDA user, so I'd have to say NVDA reads it in more detail, only because I never wait for JAWS to fully read it. if I have random EXE files in downloads, the UAC prompt can also be used for that as well.
as for JAWS support and win10, last I played with JAWS, which, I can't go into as to why I can no longer do it due to forum policy, the last 3 or 4 2018 updates have caught up. at least noticeably! better than it used to be.