""I just put it in the car and set the total timing that was on the FBO spec sheet and it runs perfect.""

I didn't get any instructions with the unit but what I do know is:
18 deg initial
12 deg at 12" vacuum timing
16 deg at 2800rpms
Total should be 18+16=34

I am assuming that with the vacuum advance disconnected, I set the initial to 18 degrees at my idle rpm. Then once I hook up the vacuum advance to manifold vacuum, this should add about 12 more degrees and my idle rpms will go up as soon as I plug in the manifold vacuum. Then I was planning on just lowering the idle rpms back down and rechecking the timing at idle.
Is this correct?
I believe that the most important part is that I have at least 10" of vacuum in D with the brake applied. Is this correct?

Thanks