Last summer we were in the midst of 4 applications, so I sometimes mix up which ones required which things. That being said, this is what I recall. I filled out the academic information about my son/student. The questionaire from USNA came via email (not the same account he uses) and I filled out the forms on-line. My son, who is also a Plebe this year
had spoken with his current college instructors, who did not feel that they had yet had enough contact with him to fill out the lengthy form. (He took distance education classes at Northwestern College in St. Paul, MN.) The coach and community member forms were strong enough in scholastic reference that "a family member's" opinions were not considered to be unduly biased. If you are uncertain about any of the reporting for homeschoolers, call or email the admissions office with your questions. They are very helpful, but you need to be as professional in all your correspondence. I always refer to myself as my student's teacher and academic advisor. When you send in transcripts, they do want to have course descriptions, I also included a chart of the grading criteria. I would suggest that there is no such thing as overkill when representing your student's home education record. ---Back to the original question, if you have another teacher who has the credentials and experience to formally respond to the questions, then use them if they are willing. If not, do not hesitate to put yourself on your candidate's application. Be sure to use the comment section to explain your qualifications and curriculum as well as any other helpful history or data. (Count words, characters, and formulate your responses carefully, you are representing your candidate's education.) Best wishes.
PS Hold your heads high, past homeschoolers are a strong part of our academies and are not looked down upon in the application process. A PM would be welcome.