Your best bet may be to tallk to a lawyer. The terms of that contract sounds a bit stringent and restrictive to maintain a livelihood should you decide to go elsewhere.
Agency nurses often have that no-compete clause in their paperwork that prohibits them from accepting a position with a facility that they take an assignment with. And they are held to that clause for a fee or 'waiting period' too, by their agencies.
As I said, your restrictions are rather severe so it may be in your best interest to consult a labor lawyer familiar with those kind of contracts. There's probably something to it, or else your current employer's legal eagles wouldn't have had it there in the first place. I'm sure they pretty much checked it out for themselves and think it's ok. Just pay for a consult and get the right info for yourself since you've concerns.