H1, H4 Stamping (Dropbox, Interview, Travel and Timelines)

Dear Experts,

Situation - I have my approved H1B (changed company and have gone thru premium processing) with expired i94 (31-Mar-2021). My spouse and son’s H4 visa extension application are still under “Case was received” status; filed on 15-Mar-2021 finger print taken on 7-May.

Intention - I want to travel to India along with my spouse and child (Indian born) in the month of Jan’2022.

Question - Considering travel restrictions, dropbox appointment unavailability and delay in receiving approved i797 of my spouse and child; looking forward for advise on

- What is suggested and I should be taking care of w.r.t. timelines, next steps in terms of getting Visa Stamped and travel back to USA.

- Can my spouse and child travel back to USA on H4 stamped VISA, with/without NIE?

- Do I need to take multiple appointments; one for myself to avail dropbox and one for my dependents for interview (if they have not got their extension approval by Jan’2022)

- Shall I book my travel tickets or wait until stamping appointments are secured?

- I believe H1B visa holders with stamped VISA can travel back anytime to US, in this COVID situation?

- Roughly how long does it take to get an appointment for stamping and travel back to US - any unusual experience or anything requires to be carefully considered?

I tried to search for these answers but I am not finding as per my situation and complete.
Requesting you genius friends and experts to help me with valuable guided path for travelling to India and back to US with a stamped Visa.