They'd probably lose money on the stocks with the way things are going. It'd let the owners offload risk. The residents are free to use the money to buy stocks if they want to.
They're only extra if the version with fewer steps works. Communities that can host datacenters have leverage. People who want to build datacenters have capital.
Where? Because everything I can think of that comes close to a working UBI has a funding model behind it.
Sure. How many of these exist?
If some steps take something out of the realm of theory into practice, they aren't extra.