Wow! What a little tiny mortgage you have! I'm impressed
The refi. still makes sense if you're planning on staying more than 4 years (which it sounds like you are.) 0% interest on your credit card is hard to pass up, but if you're going crazy working so much that counts for something too. (Of course you could take the extra payment you're paying on your house and apply it to the credit card with the $4000 balance? Would that allow you to work a bit less?)