Yes.
Yes.
No.

8)

Most folks use a combination of Pt and Pd for their prints. If you use NA2 you will get Pt salts, because that's what NA2 is. So you will get a mixture of Pt and Pd. I do believe that all these compounds are sodium salts. Don't have the bottles in front of me, so I can't confirm.

There is an article on the Bostick and Sullivan website that explains how to use the NA2 contrast agent. I started using it last year and it works very well. Much better that the "evil #2 solution" as descritbed by Jorge.