Agreed, the first step is gathering the raw data in a centralized unambiguous form. Having each player have a unique identifier is pretty essential.
As far as data from other events. Things like regionals+ would be great if we could get it. But harder to get. I don’t think store championships or gnks would be good because it world discourage “fun” play in favour of competitive play.
I think some sort of weighted system is the answeer here. DCI gives you points for all FNMs you do, as should all reported GNKs, but SCs or Regionals or Nats or Worlds should mean more. I want to do the ANR ranks, but my skill is below my dreams at this point. Let me study SQL and some development kits for Android/iOS in the NEXT few months and I might have something, but definitely pass me up for a more capable dev.
Is there a reason that you couldn’t use the Challenge Boards that the Stimhack League has been using?