US Immigration from Japan

I filed my N-400 at the end of March 2020. Finally I got an appointment for biometric today.

Did USCIS review my application while I was waiting for the biometric? Or USCIS starts reviewing N-400 application after the biometric?

I am not sure when my interview can be scheduled, but the portal at USCIS site says my case is planning to complete by the end of March 2021 which is 4 months from now.

Filling out the I-129f and on page 7, Part2 Item 38 It says to put the passport number and expiration date in if the Beneficiary is in the U.S.
Should I leave this blank if she is not in the U.S. currently or would I want to still put her passport info in there anyway?

Title says it all really, I have seen people saw on this board that you need 6 months of legal residency somewhere to get an interview in that country. Well what does that mean? 6 months without moving to another city in the same country? She has lived in Japan and only Japan for years, does it matter that she has moved to another city? And is it 6 months from the time of applying or NOA2?

Even writing in pen pushes the limits of the space provided, does the following sound like a good plan?
Writing the address in pen to the best of my ability and also putting an index card over the paper in the binder?

Oh also, my fianc is Filipino but has lived in Japan for 6 years, can we choose Tokyo for the interview location?

Is the tax transcript sufficient for the K1 interview, or is anything else needed like a 1040 or W2?