Question about stopover in Dubai
 

So I have a 13 hr stopover, but I don't want the free hotel they are offering and would rather stay at the airport and wait for my connecting flight. Do I still have to go through the immigration hassle if I stay in terminal 3 until it's time for my connecting flight? Do I still have to hand over my US passport to security within terminal 3 if I don't leave the airport? What is the process like if you just wait at the airport?
Thanks.

You find somewhere to wait and you sit down there. Simples.

You will have to go through security where you will show your passport and boarding pass for your connecting flight. No, you dont have to hand it over, nor do you have to go through passport control and get the passport stamped if you are remaining in the airport.