Thank you for requesting me.
There is no grace period following termination from your employment. You would be out of status as of July 29, 2016.
1. You can attempt to apply for a COS from H1B and H4 to F1 and F2 but by the time the school issues the I-20 you will be weeks out from having pay stubs to date of filing the COS and it probably would be denied.
Your best and fastest solution is to have your employer provide you return transportation as required and for you and your wife to apply for your F visa stamps back in home country.
2. The I-797 fee receipt for the I-539 change of status does not give you any permission to attend school but allows you to remain here while the applications are pending in a period of stay authorized by the attorney general if TIMELY FILED. Your application would not be timely filed because you are no longer working and in status.
See this USCIS link
3. A new employer can apply for a change of status from F2 to H1b but you cannot begin work on the receipt but have to wait until petition and change of status is approved.
Of course, I am sure you understand your positive rating is very important to me as we are not on salary and that is how we receive compensation, you choosing a smiley face or 3+ stars
In the future, you may begin your questions with “FOR JUDITH” and I will be your personal immigration expert.