Not a bad idea, but from my "proxy" (=play by mail) slot car racing championship last year, I can say that to keep interest, you have to make the games quick and simple.
Since each coach will not play his team, you cannot speak about real home and away situations. In a way, it's a journey season
In my opinion, 10 teams (for example) = 10 regular season games. Each team plays once against every other team.
victory = 2 points
draw = 1 points
defeat = 0 point
goal average bonuses for final draw situations.
4 best teams of the league = 2 semi finals
2 last winning teams = championship final/bowl game.
game ruleset : each people can use his own, but has to explain it to other coaches before the game.
Simple, fast and effective system. It could be look too simple, but believe me, between the daily obligations everyone has, mailing delays, job, family and all, that simple system with only 10 teams, it could last during months and months.
Last thing, about my direct live broadcast gaming system. I'm very enthusiast about it. I don't want to interfer with the project on that topic, if you feel that it's quite out of topic (since as I said, it's not really solitaire play).
I will create a topic in another section of the forum, I believe. And I will certainly search for other coaches to test that idea...If you think that idea can be used for the play by mail solitaire league, too, these test games could be considered at preseason games, to test the do-ability of it, test for mail packages, etc...