Hmm... I'm puzzled by your statement that AZD wouldn't necessarily accept all the members of NBO.
When my local went AEPhi, all of us were automatically accepted. We met as a group with some of the national officers, mainly so that we could mutually decide if our ideals and goals were in line with each other's, but we were not interviewed individually.
Maybe that's just AEPhi's policy, I don't know - but why would AZD or any other national want to break up an established local? Even if they only accepted some of you, couldn't you just turn around and bid the rest? I can understand a national turning away women who hadn't made grades or are unable to meet the financial obligations, but I can't understand a national turning away a member of a local because "we don't like her".
I may have missed something, but what were the other 3 organizations besides AZD that expressed an interest? You mentioned something about XO?
Good luck - things seem to be going great!