2) No you cant. You must use exploits/vulnerabilities usually. The only vendor that I know of that just sends you unlock code on request is HTC.
3) Yesterday I played Diablo 1 on my windows 8 machine. 3 months before that - Lotus (the game). That is measured in decades. How backwards capability is debatable.
4) Yes linux is everywhere. But invisible - moving the servers, or hidden below deep layers of customized software in the consumer devices. The linux ideology - nowhere to be seen.
Having the ability to run simple firewall to control what processes use your data plan is hardly absolutism. Or editing memory value of a running process.
Edit: Do you support the Chinese Great Firewall - because there is no difference in restricting access to internet and to software in principle?