Yeah yeah call me a lib for not having Linux, let me just shit on what I had to work with (I'm being dramatic but still):
Not only is there not an option for making a guest account like on Windows 7, they also forbid you from creating a new local account by the first name "Guest" !! Calling it "Visitor" works but sounds kinda stupid imo. Why do I gotta go through hoops to let people use my laptop without worrying they'll see gay porn or personal journal entries??
Also, you're allowed to make a new user without a microsoft account, but it seems like they intentionally make it seem like you can't at first (it'll ask you for a microsoft account and have it seem like the only option, until you get more options after clicking "I don't have this person's sign in information")
Windows old can be removed. It's a leftover from the upgrade process so it can roll back if the upgrade failed.
Windows doesn't do trash disposal well, so it remains; similarly, you should see how much old crap is left behind from updates that you've already installed and don't need local copies of anymore.
Kinda funny they prepare for a roll back, while, I dont think, providing the option to do so.