Emma, your quilt is beautiful. You have some great suggestions to consider. I know you will find one (or several) suggestions to border your quilt.
I agree with a more neutral border so the quilt could be used with any color on the walls....maybe a softer color so the top with pop....the focus is the top and not so much the border....special effects in the quilting of the border is an excellent idea and wouldn't detract from the top.....appliques etc would draw the eye away from the top (IMHO).
Quilting involves a lot of decisions! Do what makes your heart sing
Let us know and see what you decide. Thanks for sharing this morning.