h4 child 18 years old - stamping in India (Questions on In-person interview)

[THNK1]

Three questions:

My son is currently 17.9 years old (as of July 2024). He came to the US 6 years ago in 2018 on an H4 visa and hasn't returned to India since. In August 2024, he will start his undergraduate course in Computer Science at Virginia Tech.

1. We are considering getting his visa stamping done in India so he can visit his grandparents. Should we send him before he turns 18 (requiring an in-person interview) or is it ok if we schedule stamping interview slot after he turns 18 in October  (i.e., in December or next May 2025) ?

2. Also, is it acceptable for the parent/mother, who holds the H1 visa, to remain in the US while sending him alone to India for stamping? Considering he is an Indian boy who will be pursuing his studies in the US, will it be challenging to obtain H4 stamping for him? Or you suggest mother / h1 holder also to accompany to India for stamping 

3. If we create a DS-160 now, pay the fee with the current I-797 visa which has end date in November 2025 , and schedule a slot, can we later update the DS-160 with new I-797 renewal dates for him (as we have plan to apply for H1/H4 visa renewal May 2025) if we receive the renewal before the interview slot ? 

Thank you for the help to reply us, your reply really matters to us.

Edited July 11 by THNK1