take it from me - go with a moderate courseload (14 credits doesnt sound bad) but clean house. you will have no excuse no to pull some sparkling grades. and you can use the extra free time to do other fun, exciting, interesting stuff.
a friend of mine went to school with me, took a light load (12-14 credits) and pulled straight friggin A's. EVeryone looked at her like she was some kind of wunderkind - nobody ever remarked - oh but you only took 4 classes. So dont sweat it.
Its all about good grades. Look - you take 4 classes, and do really well (A's & A-'s) nobody really knows your downside - i.e. IF this person was taking a heavy courseload how would they do?
BUT taking 5-6 classes, pulling B+'s and B's - they KNOW how you would do.