only way to achieve this with renoise & pulseaudio, is to use jack as renoise output, and route pulseaudio output to jack, either via jack-sink/-source or jackdbus-detect pulseaudio modules.
the alsa-pulse plugin routes sound from alsa applications (that don’t have pulseaudio support like flash player) to pulseaudio, and it is something your system should have if it is using pulseaudio, so I’m pretty sure mint should do this already by default. It doesn’t work with renoise however, because it uses the alsa device ‘directly’ and prevents pulseaudio from using it.
It could be possible to get renoise to use the alsa-pulse output, but that would require changes in renoise code, or it could be possible with some hardcore .asoundrc tweaking, although I’m not sure if that would be the best solution for music production anyway. It would actually be interesting to hear if renoise devs have considered this.
anyway at this point using jack with pulseaudio seems to be the only option. I think I could write a howto, since this seems to be quite common issue, but I hope this helped until I get it done 