Remember too; that your high school and counselors are only involved if the college classes you want to take are either: 1) Fulfilling a high school credit; 2) Being paid for by the high school/district; or 3) If you will be taking the class during normal high school hours and scheduling is required.
If you want to take a college/community college/online/etc... class in your own time, with your own money, and not applying it to your high school requirements or transcripts, you don't need any permission from the high school or their counselors.
Mind you, some colleges may have certain requirements, such as age; but generally speaking, if you can pay for a class, they don't mind you taking the class. But again, unless the college class you're taking is fulfilling a high school requirement, the school/district is paying for it, or it's being taken during normal high school hours where scheduling can be affected, your school and counselor have no say in what classes you take on your own.
I do want to emphasize what I wrote in a previous post. If your academics are that good; and you've fulfilled all your most challenging class requirements for a good academy application; then you might want to look at the rest of your application and see if MORE ACADEMICS is really the right choice. If you are weak in leadership experience, weak in volunteering hours, weak in athletics, weak in clubs and extra curricular, then those are areas you should be spending all this extra time on. I know first hand individuals who applied to the academy with 4.0 gpa's; ALL AP classes; 34+ ACT scores; and they didn't receive an appointment. Why??? Simple.... That's ALL THEY HAD. The academy doesn't want just 4.0 gpa/AP/IP 36ACT students. This isn't Harvard or Yale. They want a well rounded person. A person involved with teams. (Athletic, Work, Groups, etc...). They want individuals with leadership experience. They want people who put OTHERS ahead of themselves. They want individuals who are diverse. IN ALL ASPECTS.
If your academics are really that good and you've exhausted additional challenging academics that your high school has to offer; then look at the rest of your application. Generally, when I'm asked from applicants if they should take classes at the local community college, the only time I recommend it is if their high school doesn't offer challenging classes. In Wyoming, we have a lot of high schools that are so small that they don't have AP or IB classes. We have a lot of home schooled kids. Those kids I recommend that they look into some community college classes to show they are taking challenging classes. For the rest, I try to have them concentrate on the rest of their application so they are well rounded in all areas. Not just academics.