> Every single time it updates, which it forces on me I come back to add to buy Office 365 even if I already have it.
Yes, it's dumb, but you can disable it in Settings.
> On one computer the File Manager is slowed to a crawl, the image viewer slows to a crawl if I hit left or right arrow keys.
While I'm not going to say you're not experiencing this, this isn't something I've seen personally. So it isn't a universal issue.
> The built-in antivirus has a feature to send “suspicious” files to Microsoft, with zero audit trail of what it sends over, and its on by default.
Audit trail is in Event Viewer.
> The various UI inconsistencies, theres weird XP goop mixed with the modern UI.
There is even Windows 3.x UI mixed in. This hasn't changed and is nothing new, nor interesting.
> I tried to make a new user account one time and it told me I couldnt because I needed to use another feature within Windows to do so,
Creating a new account doesn't require a Windows Feature to be added. Compmgr.msc.
> Everything you type into the start menu goes into a Microsoft backend.
No. Just wrong.
It sounds like you should educate yourself on Windows. And I did specifically mention Pro.