You rang? (I'm back.)
Interesting case. I once slammed the rear overhang of my first bus into the ground pretty hard, in a filling station driveway/curb, and Millicent has old damage from scraping. So that would be a concern.
Worse, as was mentioned, the overhang swings OUT in turns - very much against most people's instinct. The biggest hazard might be the fuel filling pump, when he swings away from the pump after refueling. Remember that filling station that was rammed by the black Dodge Charger in Bullitt?
But as was also mentioned, if he drives it with the inside of his head, it might work out OK for him.
I don't think steering traction would be an issue -- unless he reinforces the rear platform to extreme with tons of steel.
How it works out for the motorist who rear-ends him.... Hmmm.... I once watched a lady drive her car headlong into the side of a huge empty car-hauling trailer that was making a U turn. At first, I couldn't fathom how she could fail to see something so large, and I reckon the truck driver expected she would see him and cut him some slack. But then I realized that she saw him just fine, and aimed calmly and skillfully to pass behind... his brightly colored truck, and NOT HIS ALL-FLAT-BLACK TRAILER.
Structurally, I'd have to see it up close. But remember what Archimedes said (and he was right)... "“Give me a place to stand and a lever long enough and I will move the world” It's all about leverage, and the antidote is triangulation.
As for skipping the pillars in the walls, that would also worry me. (Remember the picture of the infamous crashed Carpenter.)
Here's the thing: I'm old, and I grew up in an enlightened European country. Between those two factors, I was taught a bit about mechanical principles in school. We built levers and stuff right in the classroom every day. And at home, I played with Meccano erector sets and built Marklin model train layouts. Leonardo daVinci and Isaac Newton were "real people" with real knowledge. These days, I suspect they have been pretty much replaced by Bill Gates and Steve Jobs. Even some of the guys we hire to drive 18-wheelers are astonishingly ignorant of basic concepts like friction and heat (truck brakes on a downhill). It's scary. Nation-wide and society-wide -- not just one converted bus. This is one reason I advocate good-old-fashioned mechanical games and toys (Kinetic Sculpture Racing, Burning Man three-dimentional art) at every opportunity.
It's still Saturday here, but it's Sunday somewhere, so that was today's sermon.