Thor said:
All this is in works and nothing is permanent yet, still trying to get judicial information on cash prize for games of skill just to make sure there will be no issue
Read over the NC laws on gambling. They also include this sort of thing and outline what is and is not legal for organizations to do and what percentage the cash prizes can be without triggering a bunch of extra rules.
Make sure you get the rules for non-profits, some sections of the code vary wildly between for-profit and non-profit organizations.