1. In general, your relationship status should be considered bonafide by this point since you have already been through i130/i485 and i751 process. Most reports state the main focus is on the civics/english portion with some precursory questions about where you live/work/etc. That being said, the interviewer can ask you about pretty much anything if they are curious, let alone if they feel something is amiss or being withheld. I'm not sure what you mean by you and your wife had to relocate for work. Did you move from somewhere else to the Seattle area or did you move from Seattle to another area and not notify USCIS?
2. Looking at the historic data, it does appear that Seattle does same day oaths on Fridays as well.
Considering they state a "marriage-based N400", they are applying based upon the 3 year rule. Otherwise, it wouldn't be a "marriage-based N400".
Citizenship of the applicant isn't really relevant for N400 processing because all of the checks which are done at the earlier levels. The relationship has already been established as bonafide during the i485 and i751 process, which is where citizenship of the applicant can come into play. At this point, it is mostly about do they meet the requirements for the 3 year rule plus the civics/English test.
In case you haven't seen it, there is a tracking spreadsheet for N-400 at the Seattle FO. It looks like yesterday, someone from August 2021 received an interview notice for late July.
Tracking Spreadsheet Link:
https://docs.google.com/spreadsheets/d/1FcItCasVItCDsUNEbDu15IRQ-AbDMRJWsiljwtz5WRI/edit?usp=sharing