1. Does Blender use absolute units or allows quazi-real-life choices like centimeters, meters and etc.
2. How to create a sphere bigger than 100 units?
Blender only have 'blender units'
If you think about it though, it really dont make a difference what you label the units right? you can make the units mean whatever you want them to mean to you, 1 blender unit can represent an inch, a centemeter, its all relative.