You asked for my advice on starting a commander league and these are some of the issues that I would want to see solved before you begin.
1) The scoring system. The basic goal should be that you are better off from playing than not playing, so even the last placed player gets points. In principle you should get more points for better achievements, so for example points for finishing places in 4 player games could be 4-3-2-1 and for 3 player games 3-2-1. You need to also cater for multiple players losing at the same time, i.e. if 4 players lose at the same time then points might be 1-1-1-1, or if 2 lost together 4-2-2-1. You might like to award points for different reasons, for instance knocking a player out by commander damage, for more ideas look at the 'embracing the chaos' column on starcitygames.
2) Limits. You want to limit the ability to score in some way to prevent small groups simply playing more times, and outscoring everyone else. I'd suggest limiting each person to one scoring game each week against any other player. You may also want to limit the number of scoring games in each week, say to 5. This could be a problem if it prevents some people from playing all their games, so you could introduce the idea of tiebreaker games. What this means is that if a player has used up all their scoring games they can still play more games counting toward tie breaker points. That way they are helping others to get their scoring points for the week.
3) Collusion. Commander is free for all, but players may collude in play and in supportive deckbuilding. If you apply limits then the effect is lessened. What if anything would you do about teams?
4) Reporting. How are you going to get accurate and honest reporting? Do you want to observe games? Do you want to restrict playing times so that you can supervise. It's easier for multiplay when everyone knows that they have to play during a certain time period, and makes it into more of a party event. Fixed times could penalise some timezones: do you want different euro/asia/usa party times? Get some assistants to help with observing and scoring.
5) Rewards. You might need to have more than entry into the winners event to attract players. Do you need a sponsor?
6) Legality. A lot has already been written about potential rare commanders, and the consensus seems to be to allow any under a dollar. Are there any other cards you would ban? Uncommons are particularly hard to monitor for legality. Watch out for Kird Apes etc. What penalties are there for illegal decks?
7) Recruiting. Don't wait for people to just turn up. Get a good recruiter like andymc1 on your side. Publish everywhere, clan forum, pdcmagic, wizards forums, puremtgo etc.
I think if you can thrash out all the details and get a coherent rulebook posted then you could be onto a winning event. There are definitely a number of players who want to do this.