Some spotting Qs

[Borscope]

Ok, the guide says vehicles w/ passengers spot better due to more eyeballs.

1:If I have a vehicle w/ say; vision 40, carrying infantry without any kind of NVGs, do they increase the vehicle's chances of spotting out to the 40 hexes (and visibility is say 10)?

2: Does the vision rating increase spotting chances (within the vision range?) even if visibility is greater (i.e. TI picking out engine heat behind netting or whatever)?

3: Do enclosed/APC class vehicles differ from open-topped/tank rider in spotting ability?

4: Any chance of incorporating a "spin-search all my units" button in the future? I read that the AI has something like this in a recent patch. (My right click mouse button is about worn out now!)

Thanks in advance for any help.