I think I've played 1 physical DVD in the last 6 months It is so fast to rip a DVD to the hard disk that by the time the wife is ready to watch, it's already ripped and ready.You might consider USB over Cat5 so you can put a local DVD player strategically. I plan to put a hub inside my sofa where I can connect gamepads/DVD player/ Joystck whatever you may need.
I have USB ports by my theater TV for gaming, but they don't get used much. Wireless controllers have taken over The only PC gaming I do is racing simulations... otherwise its Playstation
and to answer the question about gaming through your extenders... no way. There is a noticable delay in the best of circumstances. Won't work for real-time gaming.