Reddit reviews Doctor Who: The Unfolding Text

Aah, yes. Books about Doctor Who. My time to shine.

I think this is what you want. I read it over Christmas, it was really fascinating and informative. Covers all the things you're interested in.

If you like (or can slog through) critical essays, this book is rather famous, probably the book about Doctor Who in some ways. This one is also pretty good.

Tom Baker's autobiography is incredible, and Richard Marson's biography of John Nathan-Turner is also very interesting - there are a ton of interviews with just about everyone.