Tesla's drive system is not quite up there yet. But I wouldn't be surprised if the next one was a hybrid, just to show hybridness off.
Perhaps, but if it goes much past just having the Hybrid insignia glued to the side, I'd be surprised. The presidential Limo is about two things. First, to protect the president from all manor of threats while going down the road (Which means armor, speed and agility). Second, maintain the illusion of being "normal" in appearance. Gas mileage or being "green" would have to be an illusion at best and unless the hybrid configuration added to the armor, speed or agility you can forget it.