Hey thanks for the detailed reply.
Normally how long does it take to process a transition from F1 to B2?
Is it going to matters if my F1 expires during the mentioned process?
It takes at least 3 months to process an I-539 COS at the service center. However, you must be in status in order to be eligible for a change of status. Consult with the DSO or an experienced immigration attorney before you decide to take any action. We do not have all the facts of your case.