AEM wideband to FlashScan V2

[mr.prick]

So AEM Grey (serial??) to position #2 on RJ14 cable. This with a switched car hot to AEM red and AEM black to negative gives me a flashing light on V2.

Yes.
A ground may also be needed. (rj12 pin 5)
Did you configure the V2's internal settings like in the .pdf in post #9?

Are "AD" input sets the ones on the bottom of V2?
Do I need AEM white to A1 and AEM brown to A2?
Does this need to be done in conjunction with the above or as an alternative to it?

Yes.
These are an alternative or addition, your choice not necessary w/serial.
No.
Each AD set has a positive & a negative.
The AEM's white wire is positive & the brown is the negative.
Choose an AD set and connect them accordingly.
Example: AD1+ = white wire & AD1- = brown wire.
Select that AD set's voltage pid then you can make the calc_pid for Lambda/AFR.