Technically, the corporation does not need to keep track of the Basis of the shareholders.  That is the job of the shareholders.

Assuming you want to do the shareholders a service, sure.  Any way you want to show how the Basis is calculated.  Using the worksheet in the corporate program works fine.

If I remember correctly, Basis statements only need to be filed with the 1040 if they are claiming a loss.  If there is a loss, yes, I would attach it by PDF.