Therefore, if I consider the game I mentioned above, and taking into account that this PP100 is an 'average' amount of points which could be scored in a given position, and that it also refers to the 'quality' of those shots, then the Matchup Ratings can tell me if my player played to the best of their ability in a given game, and in regards to their opponent, as well as what positions were more successful in particular positions. Are these fair assumptions or inaccurate in your opinion, little Guest?
If by "my player played to the best of their ability in a given game" you mean that PP100 can tell you whether a player performed at expected level, performed significantly below expectation, or performed far above expectation,
then I think your entire idea is reasonable.