The Events Database by Spdo (
http://www.spdoracing.com) does fairly much everything you are looking for.
I dont think that a central LFS World Database would work so well, as with the number of lfs events ever growing, it would be being constantly updated, not a problem in itself, but leagues grow inactive.
Also, not everyone will want to display thier league information in the same way. Personally, I dont like things all in the one place, id rather things had space to develop and grow, I dont think its too much trouble to have to register at a forum.. it takes like 10 minutes max (if there is a confirmation link to click). It also spreads interest around the outer community.
I do think however, that you shouldnt have to register somewhere just to read information about leagues or events. That should just be free-to-read and open to all, as long as its a public event.
Try the events database, im not sure exactly how much it is used by the community, but from what ive seen of it, its very clear in providing information, files and I think reminders.