MPD configuration has evolved over the past 2 years and at this time most default mpd.conf's only need you to specify the music directory (mine is in my home directory) and add yourself to the _mpd group. I'm wondering if your mpd.conf is unnecessarily complex.
There is also a configuration file for ncmpc (host and port are configurable) the details of which can be seen with
I mainly configured ncmpc to provide the song format when streaming. You might try adding a network stream to ncmpc, as long as it is connected to a host. If ncmpc connects to your host and can stream it would suggest a permissions problem with the songs on the internaldrives