Sure.
I don't recall.
I don't recall.
I don't even understand that question.
I've used guys in the 60s when their range is good. It produces some errors that you don't want but sometimes you have to make concessions.
Coaches also slow decline, and even increase development, of the learned skills in veterans(over 31-32). That said, I don't think there's much sense in putting 2M+ into hitting/pitching coaches at the BL level.