Re: The distribution of relief
Yep. From Everest Summit to Challenger Deep is only about 13 miles, and Earth has a 4000 mi radius.
If you had a to-scale globe 25' in diameter the difference between the highest and lowest spots on earth would be about half an inch. Gravity, erosion and plate tectonics keep the old globe pretty smooth.
OTOH, the difference between equatorial and polar diameter is about 25 miles due to the equatorial bulge cause by its rotation.