Yesterday, the new 2.5 shank and the straight pin have arrived. Its actually a Blue OX shank but not at the cost I first saw. I tried to get it locally, but they were still real close to $250. I found an OEM Blue OX shank for $157 on Amazon

, and installed the WD Head on in this afternoon.
I checked the trailer tongue weight, still about 880 lbs, before I towed it to the sewer dump station for the last trip of the year. I didn't notice any real difference in towing experience with the new shank. There is still a fair amount of movement, both up and down as well as sideways when it's not connected to the trailer.
I had to knock the 2" to 2.5 " adapter out with a punch, it was jammed in with the bent metal from the deformed hole in the receiver. The holes in the adapter, looked as normal as they did when I purchased the truck, no deformation at all. They were sort of oblong to start with.
I haven't purchased the anti rattle item yet, but will probably get the Trimax version. I've talked with another person that has the same truck as I do, and he has had good luck with it so far. I chatted with a mechanical engineer friend and he explained where the forces were going with that anti-rattle device.
No word back from the dealer yet about their decisions about warrantying weak metal or???
Thanks again for sharing your information and experiences.