Crash tests on MH would be terrible. I wouldn't stress much about that. If it was a huge issue there would be regulations and we would be paying out the ying yang for insurance. Fact is, RV'rs are a safe class to insure despite the obvious flaws.
MH vs 5vr is something that everyone will argue about. different strokes for different folks. You've read the pros and cons and they are mostly all minimal in the end run.
Ask yourself, how many days will you be on the road?
Do you want the livability that fivers give?
Can you deal with driving a truck around town?
Reality is most of us don't spend a ton of time driving even if we rack up miles. Some prefer toads, some realize trucks aren't a big deal. Some just want the super nice livability while other desire the set up of a MH.
Some even consider MH ownership some kind of elite class. Others don't care.
I think the bottom line is the difference between the two are fairly tiny. Truck vs toad and livability / Floor plan selection are the biggest items.