I strongly suggest that you contact a lawyer to make sure you have maintained valid status. With the facts you gave it is difficult to tell.
I am providing this general advice based on the information given and my understanding of that information. This is general advice . This advice is not intended to give a legal opinion. This advice is not intended to create an attorney-client relationship. I strongly advise you and your husband to contact a lawyer about the specific facts of your situation.
What is valid? Your application for change of status? I guess it is what you wanted, no? Hence, it should be valid. Your grace period on F1 is 60 days not 30 days. I do not understand the rest of your questions. You have to answer questions raised and provide information requested in the RFE.
The information contained in this answer is provided for informational purposes only, and should not be construed as legal advice on any subject matter,not should it be viewed as establishing an attorney client relationship of any kind.
What did the school's DSO say when you asked these questions of him/her?
Will he/she write a letter to send to CIS?
If he/she won't help, get an attorney.
PS The doctor's letter wasn't necessary & has no bearing on this application.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.