Thanks for bringing this back up.

Regarding the audio, there was this discussion more recently:

https://lists.gnu.org/archive/html/guix-devel/2019-03/msg00340.html

Which led to the implementation of some changes around user IDs.

With that patch, I still wasn't able to get around sound to work, as
explained in the thread.

Apparently it's possible to get sound to work with Docker.

Cheers!

-- 
Pierre Neidhardt
https://ambrevar.xyz/