Advanced Nation Rules editing - any experts?

[Harmonica]

I've been tinkering away at the nation rules file for England, trying to recreate the updated format for the Under-21s leagues this 14/15 season.
http://en.wikipedia.org/wiki/2014%E2%80%9315_Professional_U21_Development_League

I'm sure that FM15 will include all these but I wanted to play it for a while in FM14 anyway. If there's any experts who've spent a lot of time editing nation rules I'd love to hear any tips or interesting league structures you've created.

Some things are easy to create, like the 'Under 21 Premier League Cup' (run by the PL) which is most of the top flight academy teams in a knockout cup. I've got that working without issue mostly from simple editor beforehand. I'm still not quite sure how the game draws 'top EPPP teams' (aka category1-3 academy teams listed in a definition file), without filling two leagues with the same teams. When I used that rule for 'teams' I had teams playing in two leagues at the same time... So I've had to add teams manually 'from division' which seems like the wrong way of doing it.

Other things are not so easy, like the structure of the League 2 which sees two North and South groupings play 2 fixtures within their group and 1 versus the other region - however, having watched the default Under 18 Group in-game I know SI have set this up properly using advanced nation rules editing. I'm now trying to do the same with the Under 21s, but it's a lot of complex work.

edit: solved the leagues not showing in lists in-game issue by changing competition type to 'domestic division' rather than reserves division.

Also, I still have the default Under 21 Group 1 and 2 showing up even though I've made them inactive....

Any tips appreciated :)