Yes to auto-extending for me. Even if you don't choose to use that runway, you'll immediately know which runway is most likely the preferred runway for other pilots so it can aid in your situational awareness of where other pilots might be. I think it's a great idea.
I appreciate the detailed instructions and I did learn a few things but my use case is different than that.
I would be cutting from other applications. I personally like to keep my routes of flight in a spreadsheet on my phone and also if I'm flying commercial, I like to copy from FlightAware...