What are the limitations of the ski slope scenario as a real-life example?

Definitely a turn of a wheel. Skiing down a ski slope is going down at an angle and it's usually straight. The turn of a wheel just makes a lot more sense

the slope exists is a fairly major issue, using imaginary concepts allows for more freedom of geometric expression (subspace and hyperspacial theory). Since it is purely theoretical and imaginary greater freedom is offered to generate theories and structures.