So supposing we decide on 5 club teams - are these then fixed in stone. Is there promotion/relegation? Or does the league simply grow? Or a combination of both?

Lets say that St. Itas in the Desmond League enters the National Intermediate Cup and wins it. Under current rules they would be deemed "Senior" when entering any National competitions. Would they then join the 5 original clubs in the National League?

The issue of promotion/relegation - if a Cork team ends up last in the league are they replaced by another Cork team? Perhaps there would be some kind of playoff - the best club teams from each "local" league play each other and the winner goes into senior league?