The scenarios you present, have been discussed, ad nauseum, for well over a decade , before you joined. Bottom line? Your concerns are, at best statistically improbable. In reality. When it comes to things like having your rig, "impounded" well, that's drifting into paranoid territory. Your life, do what you feel comfortable with. I suppose that somewhere, somebody straps on a life jacket and a football helmet before they get behind the wheel, to protect themselves from risks that they are concerned with. That doesn't mean that I'm heading out to shop for a football helmet, any time soon.
Your claim that everything you discuss is "real" is something you really need to give some thought to, since it simply incorrect. Your rig is NOT going to be impounded. You will NOT be denied coverage in an accident. You will NOT be cited for NOT having a license endorsement, possibly required in PA. if you are stopped in ANOTHER state, and on and on. (many states have no such thing as an RV CDL endorsement BTW, and federal law prohibits your scenario of being cited for not having a a PA. RV endorsement, in another state)
Relax, be safe, operate safe equipment, and give some thought to refraining from creating issues for yourself that simply do not exist. If you feel better with a CDL great, but don't make blanket statements about "the way it is, on the roadways of PA", or make claims about insurer responsibility, or enforcing PA state law in other states, that are simply false. Be careful, enjoy yourself, and good luck........................