1. Windows 10 does offer a lot of performance improvements. Even if you don't like the new interface, under the hood it's much faster. Even Windows 8 was a lot faster.

2. I think there is an option to ignore individual updates. You could probably utilize that to get that to go away.

3. Windows 10 literally saves a copy of your whole system running Windows 7 on the hard disk. That is deleted after 31 days.

4. They claim that it will begin to cost money to upgrade starting next year. Whether or not that becomes reality could go either way. My guess is that yes, it will cost money just like a new Windows 10 build costs money now.

5. You can turn off a good portion of the privacy-invading settings, but it's still fairly invasive. Microsoft as a company has actually been ramping up their support for other platforms which is kind of cool. I haven't heard about any specific back doors in the Windows OS itself, but that doesn't mean they aren't there. The OS is closed source, so it's really anyone's guess.