nearly all of it mentions that you should make your dialogue sound more natural by “adding in umm’s and oh’s and stuff like that” - I've never seen that line in quite that form, but as it's clearly out there, this is an excellent antidote. My favourite bit of dialogue advice is to *read it out loud* which tends to show up when things just don't sound like anything a human being would say, but you have some excellent points about the interaction of dialogue and characterisation. (and I *heart* writhing chatty first person, where you can use that self-correcting thing; it's fun)

*adds to bookmarks*