I won't argue that an F150 pickup is probably a bit too much weight for this Motorhome to handle. However, I'm wondering if some of the setup here is the bigger issue:
...he needed to install Rough Country coilovers in the front of the F-150 for a 2" lift to get the baseplate and associated stuff to fit OK...
THIS, sounds like it may be more of the issue. Lifting a truck 2" just to set it up to flat tow? That seems strange, and not something I've ever heard of anyone doing.
Could he use a drop bar with his tow bar to bring the tow bar down to the right height, instead of lifting entire truck up? I'd think that would make more sense, and would make for a much more stable towing setup.
Sounds to me like he wanted an excuse to lift his truck up, haha. Which I can definitely understand, nothing wrong with that (we may one day put a lift kit on our Jeep, too). However, between the lift and the weight/size of the F150...It probably just ain't the best choice for a towed vehicle with that Motorhome, and getting something like the CRV like he is talking about doing is probably the best choice.