Last question please forgive me, what stops them from building a coin on the block chain that'll bypass the total sum of bitcoin users, and regulate it?
Why would I use a coin created by them when I'm using Bitcoin so that I can be safe from them and their regulations? It doesn't make sense. Even though they and their financial institutions have way more users than Bitcoin, people who are using Bitcoin are mostly doing it for its decentralized nature, there is no third party between you and your money when you are using Bitcoin which isn't the case with traditional financial institutions and that is the reason why most people prefer Bitcoin.
They can't create a coin and make it decentralized because that will be useless for them just like how they are against Bitcoin because they can't control it and manipulate everything, they can't ban people from using it or hold the funds and ask for extra verification to release the funds, the list is endless.
You mean the government will need a help of another Satoshi to set up a fresh block chain that'll be centralized before setting up their own coin? Since they won't dim it fine to build on the existing block chain due to its decentralized nature.