Good news!
I took heed of all the maintenance to square away. The car has SP-534 in it, with a nice dab of dielectric grease on them. Additionally, the PTU fluid is fresh. The previous owner must have done it right before they traded it in because the fluid was golden and see-through. Instead of using the mega-long extension method I just snaked my arm over the exhaust and used a standard 3/8's rachet. It was tight, but I got it out.
The RDU, however, I cannot get to. The Livernois exhaust covers the drain plug, so I'll have to take it to a shop for that.