Hate to be that guy, but there won't be an internet split because you won't be able to use the darknet anymore. Number 4 would also mean using only official OSes, no Linux allowed. This can be forced by only allowing the trade of PCs and mainboards with secure boot enabled and without a way to disable it or getting into user mode.
On any official OS you won't be able to install anything from unofficial avenues. You won't be the admin anymore, only a user. The Tor browser won't be available in any official store. And even if you could get the installer, the OS will forbid you from installing and using unsigned or "unknown" applications.
You probably could use your current PC for a while without these restrictions, but once it breaks or you need to upgrade its over. I hope we won't get even close to this, but it looks like we are on the way. Both, in the EU and the US. Moved along by both, left and right. The only thing we can do is look and see who positions themselves where and vote accordingly.