Just noticed your SSAT Q…the SSATs are HUGE at most of these schools. With 2,000 equally qualified applicants they need to see who has the capacity to meet the rigor of classes. Academically these schools are a CHALLENGE, and that is an understatement. Particularly for tests/exams/labs. It is sink or swim. If you are sinking, you need to seek help yourself. You will be 100% independent of your parents.
That said, plenty of 99% SSAT percentiles are denied.
One score in the 80s might work, but expect to need to balance that with the other score in the 90s. If you are testing in the 50s-70s, acceptance is doubtful.
The SSAT tests material at the high school level, so no applicants had exposure to it all in G8 regardless of the school. So, no, they won’t care that your public school did not prep you well.
So study for your SSATs. We did 2x a week tutoring in Math for 8-10 sessions to prep my son. His ELA side was very strong so he took that portion without practice. I think his Math ended up high 80s and it worked out in his case.
Again, your resume sounds good. Study up and good luck.