Hi FPH,
My DS is a rising senior and we are scrambling to get everything done. Good for you on looking for tips ahead of time! I am new here, but I have been using this forum for a while as a huge resource. Be sure to read all the sticky notes!
First of all, others here will agree that the BGO is an unpaid volunteer and will usually focus on the seniors as they have the most urgent need. Nonetheless keep trying to reach out to him/her as summer is a tough time with vacations etc. If this fails, you can also find the BGO area coordinators on this website:
http://www.usna.edu/Admissions/BGO/
Secondly, here are the main things that my son and I wish he spent more time on during the fall of his junior year:
Start practice SAT/ACT exams. Get a book and start nailing practice tests at least one a month or better, until you start really getting good scores. Don't wait on this! The more comfortable you are with the format the better you will perform. You can even get these books at the library and there are free SAT videos on the khan academy website.
https://www.khanacademy.org/test-prep/sat
Get fit! You can download the CFA instructions from the USNA site and start practicing it. Throwing a basketball while kneeling is more challenging than it looks. You want to max out this thing.
Choose EC's you care about and take the leadership role. If you are already a varsity captain or club officer, you are on track.
When January comes, the deadlines will start coming fast, but in the meantime the above items can help.
Good luck!