AF Reserve Nursing Board?

I have in the Air Force Reserves Nurse Corps for going on 10 years and have never heard of in-person boards (where the member is present) for really anything.   Typically, you interview with the chief nurse at the unit you're trying to join.  Then, they submit a paper recommendation to a board of O-6s; this board doesn't ever meet the member and only looks at the paperwork you submit.

I'd clarify with the chief nurse you interviewed with and your recruiter.  I suspect there's a misunderstanding.  The board members meet each other in person but all they'll ever see from you is pieces of paper.

I personally wouldn't worry about getting in.  It's really just a formality for experienced RNs.  If they're interviewing you at all, that means there are unfilled jobs.  The only real hurdle is passing MEPS/medical.  

MEPS is just a physical exam conducted by a government contracted physician at a centralized military processing station.  There's nothing to study or prepare for. 

The chances of getting deployed as a reservist are nearly impossible to predict.  Currently, the vast majority of Air Force reservists are subject to a 4 year schedule; you potentially deploy for 6 months every 4 years.  That schedule is always in flux, and it varies widely based on job, location, and world events.  There are certain factors that make it more and less likely.  

Nursing jobs with a high degree of training and specialization are almost always more likely to deploy: ICU, ER, OR, flight nurses, CCATT nurses.  It doesn't matter what your civilian job is.  It only matters what military job you have.  An ER nurse (46N3J) who accepted a med-surg job (46N3) will only deploy as med-surg.