Greetings.
It went really smoothly at first and then I got stuck. FOI - 3d.Thanks, Brendan, for the hint for 8d, which makes it my COD. I have just, as I type, twigged to 10a and 4d, though not sure I understand the parsing of 10a. 3-letter synonym for doctor?
Anyway, I've managed to finish it.
You are all so helpful!