I've already built an X11-capable MPD client, and getting the right
kind of FFT for spectrum analysis would be difficult without Cgo.
Native Go PulseAudio interfacing would similarly cause excess work.
The image viewer would be a lot worse in this regard, seeing as
the amount of preexisting native Go code is tiny, and it's slow.
TL;DR: These problems have already been resolved in nncmpp and fiv,
and there's no need for inferior alternatives.