No they can't - Article I, Section 10, Clause 1.
What about state bank? Is that permitted?
Sure since there is nothing in the Constitution that says otherwise, though I can't imagine why they would want to since they can't coin money.
The USC is silent in may areas.
And as the 10th Amendment tells us that which is not reserved to the U.S. or prohibited to the states is reserved to the states. So that must mean that the states have the power to expel another state against its will since that is not prohibited, right? Right?
Please read more carefully my post 806