Technically, it is possible. ISPs, both landline and wireless, could suddenly stop selling service and end it all. lol
Yes, but as technology grows, so would the bandwidth. Or would, except ISPs are stingy and don't like wasting money upgrading their network.
We have 25 letters and 10 digits that can be used in combination to create billions (randomly throwing that out there. I did bad in discrete math and combinatorics gives me a headache) of names. User names still exist, so why not domain names? There is the problem of IP addresses running out, which is why there is a push for moving to IPv6
Lol, I'm not even sure what that would mean?
Uhh, I would guess China, based on country population, and their use of the great firewall. But Australia was also starting to do some censorship as well. But no one government have control over the "entire internet" as it is not a single entity.