I think my main comment is that theres so many words oh my god. For example, the Points vs Power Level section could be:

Points and power level are different ways of comparing the overall strength of an army: for a fair game, whichever you use, both armies should be about the same. Power Level is much less granular than Points and only very roughly tracks the strength of a squad, whereas points are far more precise. It's very easy to "break" games balanced through Power Level, so its best only to use it if you and your opponent agree to play very casually.

Power level is written anywhere you can get a model's datasheet: points are only found in the codexes and Battlescribe.