Problems 1 & 2 are probably related. Run some injector cleaner through it, and check the plugs to make sure they are clean before you do anything involving a mechanic. Personally, when I buy a used car, I like to have the dealer do a "major service" on it right away - just so you know where you stand with maintenance.

There is no seat tilt adjustment per se, but I wonder if there might be something that can be done inside the seat to change the tilt of the seat bottom. Otherwise it's just fore-and-aft and seatback angle.

Yes, it is normal for the TOD to run like that. The system apportions up to 15% torque to the front wheels in normal driving.

If the front headrests are like the rears, they should come off by lifting them all the way and then pressing a button where one of the shafts enters the seatback.

Good luck with the idling issue!