Hello Mom,
1) How soon or when should F-1 (student) inform the school that he/she applied for AOS?
2) Can a person attend the Bio appointment earlier than the date on the letter?
I'm very curious to hear the answer to this question too.
What I was told is that you shouldn't inform the school you're applying for AOS until the very end (when you have the Green Card in your hard) at which point they can go ahead and close your SEVIS file.
The reason for this is that the F1 visa does not allow dual intent (ie: you're not allowed to hold it if you intend to remain in the USA permanently). It's unclear whether applying for AOS is enough to "show intent to remain" (the only case law I've found on the subject is the Matter of Hosseinpour, google it, which implies that applying for AOS does not show intent to remain), but if it does, it means that you may be on shaky ground in keeping your F1 status.
Something else I've been told is that you should never use your EAD card or Advance Parole while on F1 status, because as soon as you use either, you leave F1, and if your AOS is denied, you now have no status in the US (the implication being that if you hadn't used your EAD/AP, you'd still have remained in F1 status and you could fall back on that).
All of this is curated for a number of sources/lawyers I've spoken to, but
none of it is certain so take it with a big grain of salt. I'd love to hear Mom's answer on this.