Can one interview with 2 AA WOs?
 

or is it frowned upon by AA?

Interviews should not be a cause for concern. You are checking them out to see if they are a good fit just as they are as well. It's also very good practice for the future.

Do it. They do not care or even know. It's immaterial to them.

If you get hired by one, and subsequently quit and go to the other one, give them two weeks notice, etc. Don't quit and just not show up one day. That will stick with you in future.

I heard that if one quits (even with notice) before a reasonable time - say a year - that it becomes a blemish on the record.... Is that BS or close to the truth?

Im still applying, yet to interview, so just trying to figure out how critical it is to make a good choice for the first job...

A general comment about leaving within a year is "why?" What changed? Did the candidate not fit? Not evaluate the company well(ie, poor planner???).

Not necessarily a blemish but butterflying (flitting from bush to bush) with no advancement or obvious reason will get some scrutiny. Changing jobs that improve your resume is a sign of drive to improve. Changing jobs with no obvious goal or intent isn't.