Well, Congrats for your medical call. The only way to get an early medical appointment is to request them by writing/calling alternate days. I got medical request on 14th July, got appointment on 6th Aug, asked them every alternative day to give me an early appointment by they said we don't have any cancellation. so its luck, if they have any cancellation they can give you an early date. Lahore mein boht rush hota hay waisay.
For Medical, though its written in official mail to carry valid polio certificate but they never ask about it. If you have time you should get it cause its necessary for travelling but as far as medical is concerned, they don't ask you about polio certificate at all. You only need to carry your Passport or NIC, your medical request form.
You need to send all passports (Expired + Valid) to Embassy. Its your wish to send it now or after your medical call. if you submit your passports now to Embassy, you can show them your original National Identity Card. They just need to see any authorised government issued identity proof. In my opinion you should submit your passport and then go for medical with your medical request form.
Who mentioned FRC? FRC is required for visa, if embassy asked you to submit FRC then you must but FRC isn't necessary for Medical. They (IOM) don't want to see your family background.
Medical results usually reach in 2 to 3 working days. and if your appointment is at 10:30, you should go 1 to 1:30 hour prior to your medical appointment time cause they usually call you on first come basis. but not too early.
I hope it clears all your question.