I have a WDH for my current truck so would use it with the eco. I also want to get a sway bar for the added help with sway on the freeway. Current truck doesn’t sway much but it’s a dually so it can handle it. I don’t want to have cooling problems with the load but I’ll just have to watch tempsWith respects to the travel trailer all 1/2 ton Mfgrs recommend a weight distribution hitch when over 5k. Air bags are also relatively inexpensive and a great addition.
22 mpg is typical running around local. Highway unloaded running 65 mph would be high 20s for her commute.