Looked at your video of the surging. It could be a fault with any one of several sensors, bad auto fluid, or just wear and tear, or a combination of all. Borrow a scantool and check the A/T sensors for sensible outputs when cold would probably be a good start, in addition to a fluid change/level check. It could be as simple as a dodgy solenoid in the A/T. Does it only do it when cold when in "D", will it do it if you hold it in "1"?