[nefariousoctopi]

This is pretty much what Firejail [1] does (except the page trust level) and using it is fairly straight forward. I had some issues running separate X server though (as far as I know, this is still more or less experimental feature).

[1]: https://firejail.wordpress.com/

[nextime]

yes, this isn't anything new, just an example setup of firejail and some sugar added.