I assume that you are talking about machine sewn bindings, since that is all I do and you didn't specify.
Question 1 - Achievement: finish the quilt. Sometimes it acts as a frame to the quilt, which is something I like. But there are quilts where a 'blending in' binding looks best.
Question 2 - motivation - it is not my favorite thing to do. Also, the bigger the quilt, the more 'wrestling' with the bulk, which makes my motivation even harder to achieve.
Question 3 - No questions, as I've mastered it. I admit that sometimes I have a bit of trouble with the mitering, but that's usually because I'm too tired to think straight. That's easily resolved by taking some time away from the sewing machine.