My advice would be to get a rock solid independent contractor agreement drafted by an attorney that says that can't compete for a certain period of time after leaving your employ (usually 2 years) and have clearly defined who owns all work performed (you) and penalties if they violate the agreement. Then be prepared to enforce it in court if necessary.
Noncompetes aren't always enforceable, depending upon location and type of business. IMO, spaceylacie's just better off hiring competent help and paying them appropriately. Another thing to consider: who minds the store in case something happens to spaceylacie? Personally, I want employees who are willing and able to take ownership of others' tasks. Those are the types of people I want on my team.