Now, that being said, is the property held â€œjointlyâ€ or as â€œtenants in commonâ€. If jointly (i.e. joint tenancy or tenancy by the entirety), both signatures are required. If tenants in common, each of them can sell their proportionate interest (i.e. each can sell their half).
No. If your wife is on the deed, she's an owner. You can't sell her portion without her permission.
Check with a lender regarding refinancing.
Also, if you can explain what you're trying to accomplish--what the situation is--we may be able to provide other suggestions that will get you from Point A to Point B.