Would moving a component like the Sphere Collider for the Sphere GameObject up in the inspector have any effect on the components below it? Or is it just a way to organize components?
As far as I have seen, it is just a way to organize the components. Just be aware that if the component that you move is a parent, the child components will move with the parent. However, moving a child will not automatically move the parent.
Yes and no. Sometimes it depends on the component. For something like that it wouldn't cause an issue. In the past you'd have specific image effect components that would be affected by the placement of the components. So if you had one image component over another it would "process" them in the order they were placed.
For the most part this is somewhat rare as I haven't really seen it happen outside of that unique instance and image effects in that manner are no longer used.