The less involvement of governments and banks - the better!
Erm... either I misunderstood, or you did.
He's not suggesting any country "accept BTC." I think he's suggesting they agree on a single fiat currency to hold currency in the banks, and maybe have a shared account.
The country doesn't have to "accept BTC" for there to be an exchange there. Bitstamp is based in the UK with slovenian banks. MtGox is based in Japan. As far as I'm aware, Japan know about MtGox, and they didn't have to contact IMF or anything similar.
The bigger issue wouldn't be the countries acceptance of Bitcoin, but more the individuals banks acceptance of Bitcoin business as that tends to be the thing that leads to exchanges shutting down. On a country level, as long as you play by the regulations (of which I'm not aware of any countries that totally "ban" Bitcoin or Bitcoin related business) then it shouldn't be a problem.