From a re-applying standpoint...read the stickies on the top of this forum.
From someone who has had to re-apply, my view is the following ...
The Admissions Board is determining your ability to succeed as a MIDN (with the goal that you will make an outstanding officer). You need to prove to them that you can handle the rigors of USNA. Not to beat a dead horse, academics (mimicing the plebe course load) is essential BUT IMHO, if you can combine that with other loads (intramurals, ECAs, student government, ROTC, etc) it may help the board get a "warm and fuzzy" that you can deal with more than academics. After all, academics IS NOT the only thing that you need to worry about at USNA, there are plenty of other demands.
Best of luck.