Re: backported libpulse-dev cannot be installed due to dependency version issues (caused by the backport)
That apt output looks as though you've instructed apt to install
libpulse-dev from jessie, but you already have libpulse0 etc. from
jessie-backports, which are incompatible with libpulse-dev from jessie.
Thanks, this seems to be the culprit.
I thought I had set priorities but I commented out the jessie-backports one at some point
in time between updating PulseAudio and now.
Sorry for wasting your time with my noobness.