My best guess on discoverd is the project at https://launchpad.net/discoverd, which seems to do service discovery on the local network, but I can't be sure since the linked home page appears to be down.

This is probably because OpenDNS(among others) hijacks the NXDOMAIN response that is supposed to indicate an unreachable server and instead spits back the IP address of a support/advertising page of their own. Not much one can do about it short of switching to a DNS that follows the rules or running Dnsmasq between your computer and the DNS servers with the appropriate OpenDNS IP addresses set in the "bogus-nxdomain" option.

These kernel images and flashing scripts are so convenient! Could I make a request for bridge support? I was thinking of trying to run a VPN server on my plug, but 'brctl addbr br0' spat out 'add bridge failed: Package not installed'.

It seems like your ALSA setup is trying to use dmix, which tries to resample everything to 48khz even if it doesn't need to. You probably need to declare the specific hardware device in the mpd config. See http://mpd.wikia.com/wiki/Tuning#ALSA_dmix