Just drawing the situation out, even roughly, is already an enormous step forwards from theatre of the mind, and is doing most of the heavy lifting here. It's also not "theatre of the mind," like the original poster is implying. It's a map, just one without grid-spaces or precise distances.
Eagle0600
This works for situations where exact positioning isn't too important. When want to have AoE spells, move speed, flanking, and battlefield control, it generally because difficult to ensure that the GM and the players have the same picture of the battlefield. Even just drawing it out roughly can help a lot, but pure theatre of the mind really works best when you only care about distance rather than relative positioning and complex battlefield conditions.
Stairs provide a more difficult problem, because you can't just size them to the largest possible resident, nor the smallest. You could create steps with multiple sizes side-by-side, but that requires more space; I suspect ramps would be far more common than they are in our world as a "one-size-fits-all" solution. Can you imagine a world where everyone expects a ramp up to the second floor of their home before they expect stairs?
The whole field of ergonomics would be a lot more interesting. The diversity of body shapes means you don't just have to account for larger bands of possible dimensions, you may need to account for entirely different anatomy. These would follow through clothing, furniture, construction, accessibility laws, etc. There wouldn't be just one new shape that's different to ours, there'd be dozens to account for.
Touching on just construction for a moment, there's a concept in at least some countries of what can be advertised as livable space, the most clear example being minimum ceiling heights. With a broader array of body shapes, lawmakers have to make a decision between allowing residential buildings to be advertised with a limited category of occupancy (necessitating the creation of several classes of living space with different requirements) or requiring every residential space to be built to at least physically fit every potential resident, no matter who it's advertised to. Commercial and industrial spaces obviously would all have to fall into that latter category anyway.
Nah. Evil is where the harm your actions do to other people doesn't stop you from doing it. Neutral is where you wouldn't put yourself especially at risk or especially out of your way to help others, but you wouldn't hurt them either, even if it benefited you. Obviously there's a spectrum there, most neutral people would do harm to others if they had a gun to their head. Enjoying the harm you do unto others is sadism, which is separate from alignment. A good or neutral person can be a sadist, but their morality will prevent them from hurting others even if they enjoy it. In short, sadism provides a motive (of which there are many others), alignment provides the restriction or lack thereof.
Tl;dr if order a village slaughtered to take all their stuff, I don't care how dispassionate or purely self-interested you are, you're evil. If you murder people because you're paid to, and don't much care about the details, you're evil.
Just one. I've never had a compelling reason to have another, but if I did it would probably be just one more.