X-Plane is an incredibly complex piece of programming “underneath the hood”. If you are interested in a brief technical overview of how Blade Element Theory actually works, here is a link to a 10-minute read which is guaranteed to blow your mind.
Clarification and Learning
Documentation and explanations
Why does X-Plane do strange things? Understand and get proper control
If X-Plane seems to act in an unpredictable way, here is possibly (IMHO) the best video that Austin has ever produced. It’s quite old but still completely valid.
It’s a brilliant explanation for why single-engined aircraft veer to the left, or why flaps have non-intuitive side-effects. He also deals with joystick sensitivity issues.
The video is definitely worth a refresh-look. Click here.