The F250 would pull most medium size 5W's I pulled a 33ft & 35ft with an F250 diesel. My current 5W is 35ft and about 14K loaded, I have gone to an F350SRW for the added carrying capacity. I RV mostly out west with lots of mountains and get 11 mpg. Look for a used truck, if Ford stay 2011 or newer for the 6.7 diesel, the 6.4 had issues and do not get a 6.0 way too many common problems. Yes there are good older but there were issues. The exception being the old 7.3 but it old technology. The 6.7 will have an exhaust brake, you want one, it works, and more pulling power.
There is a fuel program, TSD, that give big discounts on fuel in truck stops. If you have an issue there fueling it's time to stop driving. (info all over the web)
Backing is an issue for many who don't do it regular but the large majority of RV parks have drive through. I solved the backing issue by taking a CDL class at a community collage. (ended up buying a class 8 and quit after 750K miles, I learned to back) Backing is repetitive, practice, practice, practice any large parking area evenings. Setup cone,s park in lined spaces, straight line back, just get comfortable maneuvering, you will learn where your 5W pivots.
Like has been mentioned setting up is exactly the same as a class A, level and hookup utilities. Auto level, I would not have ordered but now that I have had it I'll never manual level again, push a button and stand back.
Your wife's worry is unfounded, winds get bad park. When depends on your driving skills, getting uncomfortable, it'd time. Roads too bad, narrow find another way, get a Truckers Atlas any truck stop, roads are marked OK for big trucks you should be good in your RV.
5W layout is very important and I learned as I went. My current meets all our needs. Can I get to the fridge with slides in? Bathroom, bedroom? Is the couch directly across from the TV? If yes I can hit a rest area or wide sot and fix a sandwich, use the bathroom or take a nap waiting for winds to die.
I don't have all the answers but PM if you have questions, I'm on almost daily.