Good news (maybe?) today. Took my Ram in to have the N-Fab podium steps installed, and the dealership made it a full day service appointment to check out some of the other issues.
1) Clunk underneath when driving - Fixed an issue with the right side control arm.
2) Park/Drive - They are going to replace the valve body.
3) Backup brake engaging with nothing behind - Unable to replicate, but asked for any programming updates to be applied.
4) Rough transmission shifting - Hopefully resolved with a programming update.
The dealership has been great throughout the process so far, and they sent someone to ride with me this morning so I could show them the clunking noise. They're going to need to keep it for 3 or 4 days, so they gave me a loaner. I'll tell you this though - having the TSB numbers from this board, as well as sending them a link to this thread made things a great deal easier to explain and get remedied. Thanks all.