Amazing read. I think mouse movements are a crucial part of Jagex's bot watch. Since all scripts use the same API methods with the same mouse controller, all bots would have the same profile. If, according to your first quote, it would be possible for Jagex to compare profiles of different players, it would explain why Jagex is so good at detecting bots nowadays.
What I think that needs to be implemented in OSBot: let all accounts have different bot profiles (different mouse speed, accuracy and mouse movement patterns). What also would be a nice addition, is that each bot could change its behavior at random times. For example, sometimes your concentration is good, at other moments you like to afk a lot or you are tired (thereby decreasing your mouse speed and accuracy).
I thought about writing my own mouse controller too, but I failed (seeing your code, I can imagine why). So an amazing thanks for these snippets. I personally had the idea of recording my own mouse movements (say 300+ different paths). Then every time the bot moves the mouse, a random path is picked based on the distance that needs to be covered. Of course you will need to rotate and scale this path, but that's not a problem. Add some extra randomization and you would have amazingly realistic and undetectable mouse movements.