There are no hard fast rules. Hell; you don't even have to be going to college. You can work at Walmart and apply to the academy.
I will say however that if I was to "Rate" the tiers, it would be: 3rd place: Not attending college at all. 2nd place: Attending college PART TIME. 1st place: Attending college FULL TIME.
Now; you can look at it any way you want, but it is generally accepted by MOST Colleges/Universities; which the academies fall into this category; that 12 or more credit hours PER SEMESTER, is considered FULL TIME; with 15-18 credits being the NORM. Under 12 semester hours is considered PART TIME.
But like I said: Anyone can apply to the academy. (Assuming they aren't too old - 23 years old prior to attending Basic Training). So taking college classes, even 11 credits, is definitely better than not attending at all. And if you are also really involved in sports, volunteering, community, clubs, work, etc... then that is really good and the 11 credit semester will look really good. If not, it's still better than not taking any classes.
Sorry; but there is no RIGHT ANSWER here for you. No one can give you the "Right" answer. It doesn't exist. This is part of the "PERCEPTION" area of applications. Just like how you dress and address an interviewer is a "Perception". Some rate you low if you are casual and not a suit. Some don't care. Well; this year's selection board will give you "X" amount of points for college, classes, grades, etc...Will the panelist give you more/less because you were full/part time? No one can answer that. Will they look higher on someone who volunteered at Meals on Wheels (Because their parent happens to be a recipient) compared to volunteering at the Girl's Club? I think you understand what I'm saying.
Just do what you do; do your best; enjoy life; and let things go where they go. The academy isn't the end of the world if you don't get in. It's not the only way to being an officer in the military. And it's definitely not worth you trying to be something/someone that you aren't, just to try and anticipate being what you think they want you to be. Best of luck.
