What's the problem here? Are you roaming all the time and that imposes a unreasonable cost on you? You want to stay totally off the grid and using VPN/tor isn't enough?
>Also, will Google let me browse the web with "my own OS" without their proprietary services installed on it? (see 1)
Having control of something isn't the same as third party services granting you access. Many online games only supports windows with secureboot and TPM enabled, but that would be a silly excuse to say that you don't really "own" your PC.