These videos will help with the angles.
https://quiltwithmarcibaker.com/binding-inside-angles/
A second that might give you ideas.
https://quiltwithmarcibaker.com/finishing-quilt-edges/
In fact, even more tutorials here for you.
https://quiltwithmarcibaker.com/quilt-videos/
We used her methods in our LQS class to bind a Christmas tree project with different angles. I refer to them frequently. Good luck deciding on the finish!