So at least I was right about one thing… I am embarrassingly bad with guitar maintenance.  The buzzing wasn’t being caused by the neck angle; it was being caused by worn frets.  So I made the wrong adjustment, which led to the intonation problems.  Bill at Guitar Factory got the neck back into alignment pretty easily, but I need my frets redressed.  That will take around 2 weeks (when I eventually decide to leave it with them).  In the meantime I can try to play lightly while I record (to minimize buzzing) or I can use one of the Ovations (which I usually only play plugged in).  Decisions, decisions…