im not think government will enter to buy or sell or start it is own coins like bitcoins because it is out control of central bank and cant add more funds to it
I dont think so, government will definitely invest in bitcoins in order to make their economy strong and to make it more stable through bitcoins. Government will also try to impose certain restrictions on bitcoins transactions in order to control its price and for monetary purposes.
But it was hard to monitor and to control theres no way yet to control it, that's why China bans the ICO and exchanges since it's not only in their country goes it's distributed to other countries due to Ico.