Ads appeared for me after a month of usage. I assume there's some A/B stuff, and usage indicators used to determine when this should happen.

If you disable Cortana, a feat in itself, the file system search functions die.

Your last point is not really upheld. Greater flexibility existed in previous versions of Windows. Though different solutions to the inbuilts existed, they weren't popular. However, dictating which browser, through inconvenience, is harmful to the web. IE6 stands to that memory.

Forcing telemetry down users throats, so you can better predict them, is spying. It won't result in products for user needs, it'll result in making users think they need less.