Hi
Regarding the point about 'hiding' the PhD bit, I've been advised that publishers do not like to read that research comes from part of a bigger work, i.e. a thesis, so I've never mentioned it. I just say that so-&-so paper arises from a two-year study into etc....
The self-plagiarism bit is, I admit, daunting! I cheerfully say that I've written 25,000 words of my thesis, but then realise I've effectively 'cut & paste' chunks of that into 1 published article & another awaiting approval, leaving me with some significant re-writes ahead. Oh joy!!