Given that a four wheel design spreads the weight to four wheels instead of just two, four wheels can obviously move more weight more easily than two.
Gonna have to disagree just on this point. Unless you're worried about sinking into soft ground or something, two wheels can take the weight just as well as four. Fewer wheels is often more maneuverable and there's less friction. I mean, you specifically mention wheelbarrows which show this trade off; stability for easier rolling/maneuverability.
I'm not sure about that... Probably just caught a whiff
Wait, is that what cyber-sex is??
From the US Department of Justice:
Hate Crime: At the federal level, a crime motivated by bias against race, color, religion, national origin, sexual orientation, gender, gender identity, or disability.
So is their argument that owning a Cybertruck is a disability? Because they might have a point there....
You can do both. Saying they've supported dictatorships doesn't mean they haven't also supported democracy. It's bordering on being a non sequitur.
That's my concern as well. Seeing what happened with the cheap hoverboards and ebikes makes me wary of being too lenient on these.
Expanded polystyrene
Sounds like you're describing something like the Monowalker
There are some people who have done DIY hiking trailers by chopping up youth bikes too so maybe look into that as well.