Robert Maxwell wrote:
Non-interference is the rule unless and until someone asks for help. If the Ba'ku sent out a general distress call while being attacked or forcibly moved by the So'na, the Federation would have more than adequate justification to intervene.
The Federation Council would seem to disagree after refusing to get involved in the Klingon Civil War until outside influence was found.
Since they're the same race and are fighting over resources, I can't see the Prime Directive being interpreted as anything other than "the Ba'ku are on their own".
I'll have to hit the other points later as its a pain to edit on the ipad.