When reporting a data error, include the page URL of the player or club — it gets fixed much faster.
A weighted sum of countable match actions. Every weight and a worked example are on the method page.
Leagues are added gradually; everything covered right now is on the leagues page. If there is one you want to see, write in and it goes on the list.
Fair enough — and because the formula is public you can point at exactly where you disagree. Tell us which action weight looks wrong and it gets reviewed; the weights were calibrated against real data but they are not final.