It's obvious you like him.
Have you asked him why he is looking for work out of town or considering moving. You seem upset about this so why not find out more.
It seems to me hes trying to be considerate of you but perhaps you are making things more difficult than they need to be.
Pretending you have other possible relationships doesnt help him any. It only allows you to feel better about yourself. What about the possible impact that had on him when you told him?
I understand your apprehension, you dont want to get hurt and want to know how risky a relationship with him is.
The thing is, he might be going through the exact same thing considering you.
You need to decide what you really want. Relationship or friendship or nothing. Once you decide on what you want then ignore all the details.
Things dont always work out, but if you stop yourself or sabotage it before anything can start, you arent any better off.
Risk is worth it.