Goood gooood, you are pretty smart man. Except for you know... those large sites and banks will need to have smaller fees than the network. Will they be able to do it? Will there be serveral competitors?

Remember, transactions will be made in the blockchain, because you require trust, this is actually the better money solution, what makes you think that account numbers backed by nothing else but pure database cell rows will be trusted more than peer transactions? And transactions in the blockchain will require taxes, that everyone agrees to, especially those that can supply blocks. They decide what the tax is, and what fees they include on what transactions they bind.

How low can we go? Let's find out! In 2038 something... but keep trying, you almost cracked it man...