If your own intuition isn't enough to answer the question, then I suggest that you learn more about basic RV-chassis design. Why did the diesel pusher motorhome evolve into what it is today? IMO these RV forums will not answer all the questions that you are asking (or should ask).
There is no end to how much you need to know, in order to make the best decision. And, nobody else can make it for you. For example, if you were to ask me to make the decision for you, in the first place, I would NOT consider any gasser. And then, you would be stuck with a diesel pusher of MY choice. Surely, my needs/my experience plus my budget are different than yours. I'm not much help, really.