|I did the oil pan on my TT with engine in. Its technically easy but physically difficult.
If you're planning to perform all that other work then remove the engine.
If you do it with engine in, replace the rubber oil return lines on the side of the pan. I also replaced the o-ring for the oil pick up. Good time to replace the steering rack bushings and steering shaft ujoint if needed.
Use air to blow out all the oil from the pan bolt holes, and practice a few "dry runs" putting the pan up because you'll find out it only goes back in at a certain angle and kinda slides against the trans spacer plate...and its easy to knock the front/rear rubber seals outta place if not done just right.