Thank you for sharing. It's too much for me to comment on all of it (and I don't have a comment on all parts regardless) but here's a few points. The ReCaptchas I got in 2015 were literally unsolvable. Google's throttling mechanism worked such that if there was too much traffic from one IP address, they'd block it, but in the meantime still present them an endless sequence of captchas just to have people solve more problems for them. You mentioned training AI and the problem is that that's exactly what was happening. Anyway, you could detect the fake captchas by clicking the voice captcha button, then it'd be upfront about it and say that you're denied access. But you already knew that when you were presented a captcha as a Tor user.

You're right about fingerprinting. I've used https://fingerprint.com/ and it does appear to track me across sessions.