Boy, that's a lot of reading.
Have both (SRW's and DRW's). Bigger camper fits and drives better on dually. Done.
Have had dozens of rocks stuck in between the duals. Anyone that hasn't, just hasn't driven enough yet. Always, ALWAYS, carry a 2# hammer.
No, duals are not as good off road. Seriously, I would never take my camper up trails that are "off road".. I take our rig up places that people cringe at...but it's not "off road". It's a gravel/dirt road that I'm confident I can get back from. It's 100k...imagine the tow bill.
Snow, no, they're not as good either. I drive in snow more than probably 95% of the TC'ers. The rig does fine. No, single wheels are almost always better.
Different needs, different tools. Wouldn't ever think about putting our camper on a SWR.