Slor - thanks for your detailed response!
Home advantage - does it exist? It is not as if you are asking the away team to play on an unfamiliar course. I took a look at the stats from this latest regular season. The home team won more games in Div One, but in Divs Two and Three more games were won by the away team. Besides, if all divisions had uneven numbers of teams in, each team would play the same number of games home and away (ie 7 teams = 3 home and 3 away). I still believe the league format to be the truest test of form over a season, and not the tournaments which are one-off games where anything can happen.
If there really is an appetite for playoffs as you say, these would be better limited to relevant teams only, so, for instance, in a league of 7, position 1 goes up and 7 goes down automatically. 2 and 3 play-off for the second promotion, and 5 and 6 play-off for the second relegation place. Much simpler and shorter I know, but as I said earlier, there are other tournament format competitions that can be run that can be separate from the league and involve everybody (much like League football and the FA Cup in the UK :)).
Keep up the good work mate!