I'm about to go take my CFII written test. I've already taken the FOI.

So I have a multi part question.

A- Do I need a logbook endorsement or something to take the written?

B- After I finish the CFII written test, I've been told it's the same as the IGI test. Is this true?

C- So if that is true, I'm also told I can take my FOI and CFII test results down to the FSDO and they'll issue me a new certificate on the spot making me an IGI. Is this true?

D- Does the same hold true for when I take the CFI-A test? Take those results down to the FSDO and they'll make me an AGI?

E- If I'm about to be a full CFI and CFII anyway, is there any benefit to being an AGI as well? Or is it just something extra to throw on my resume/ business cards?