JMU of course is a state school, as is Tech and UVa. Liberty of course is its own animal. It came up with the cash, and will do it it's way.

Decisions for ODU and JMU to go to FBS requires approval from the Commonwealth of Virginia. I'm sure UVa would lobby hard for the Duke not to be FBS

You are correct that Virginia is big enough a state to support five FBS teams. But if you're UVa or Tech, I'm guessing you lobby up the chain to discourage the state from bringing JMU to the table.