Air quality can certainly be impacted by density, but neighbourhoods that aren’t car dependent promote exercise by giving people the ability to lak or bike wehn going out instead of driving (which can also help the overall air quality).

It works pretty well, and that was without customising the controls. You definitely feel the limitations when doing some more complicated things like wire layouts for circuits, but it can be done. When I later played the Exotic Industries mod, then it felt like it wasn’t quite enough (configuring radial menus helped though).

I played a whole run of the base game without mods on my Steam Deck in handheld mode and found it just fine. It uses the extra buttons on the back quite effectively.