Kindle Unlimited + Purchase Questions

Two questions:
(1) Suppose someone checks out (reads) a book with their Kindle Unlimited (KU) membership, then returns it and later buys it. Does the author/publisher get two payments, one from the KU program and the other for selling the copy?

(2) If someone uses the Amazon link on BCTS, but checks out a book with KU rather than purchasing it, does BCTS get any benefit?