Just don't use the express settings when you install 10, all that stuff is plain to see, not like it's hidden and it's not like LinkedIn, the NSA and Facebook haven't defiled your personal info to dust already.
Don't sign up for one drive, don't sync it, don't sign into it. You can even set it to not load with windows (reccomended imo) I keep my own backups and system images.
I like 10, it definitely runs quicker than 7 and the UI is very nice
Been using automatic updates for years, once in a great while it causes a driver issue but it's never been the end of the world and I don't expect it to be.
All in all as far as Win 10 is concerned unless you're one of those Jared Fogle types you got nothing to worry about, As with any internet activity practice safe and use common sense... Or at least use a Proxy!