Nice report. I too am impressed with how the Hemi handles that load.
I haven't towed enough with my Ram yet to know for sure but I do know that my Ford burnt noticeably more fuel when using cruise control while towing the trailer. I don't know why and hopefully this won't be an issue with the Ram because I like using it. I really like how the display shows the exact speed the cruise is set at in these trucks.
In regards to your trailer brake controller issue, I think you are right that it is an issue with your trailer. My truck recognized the trailer instantly when I plugged it in and the controller worked great. I also like how it automatically disables the back up sensors when connecting the trailer and the "trailer trip recorder" is really cool; it tells exactly the distance towed and the amount of time the trailer has been towed.