RE-Filing H4 and H4Ead with pending h4 notice

I was on H1b when my Job ended on Oct 10 and i applied for h4(First H4)on dec 9th ( which is on grace period)and received my h4 receipt! Now my husband changed his job and since he had to do amendment i’m thinking to re-file my H4 and H4-EAD along with his H1-B(he had approved i140) in premium processing ! .

QUESTION 1- Assuming, the NEW H4 gets approved within the 15 calendar days then what will happen to the current H4 petition which was filed on Dec 9th 2024? Does it automatically gets invalidated once the New one approves?

QUESTION2- If i get a job can i transfer back to h1b with h4 receipt notice or do i have to wait till i get my h4 approval?

Question 3) - Can i go to india while h4 is pending and get my h4 visa stamping and later withdraw the H4 petition which i applied on dec9th 2024 ? (does it put me in a situation where i ll be out of status from dec 9th till date as i moved to h4 on grace period?)

If you file another H4 application, USCIS will technically have to approve your first application as it serves bridging the gap between the period of authorized stay during grace period and expiry of your H1B status amd then they can approved your second application.
My personal take on this is not to apply for 2nd H4 application and that once your spouse’s H1B is approved , send of copy of that with a cover letter to the USCIS office processing your H4/EAD application so that it saves an RFE response time if USCIS raises one and asks for a primary H1B status proof as your spouse changed employer.
Consult an attorney before filing another H4 application and potential consequences.

Because you applied COS during grace period, I won’t take any chances in case if your H1B gets denied , you will go out of status and may need to depart the US immediately.

Ideally your COS application is treated abandoned once you leave the US while in processing but I would definitely send a letter to the USCIS center processing the H4 application letting them know you left the country on specific date and wish to go f9r visa stamping instead. While your H4 is getting processed you are considered in an authorized period of stay.