Voicemeeter
http://vb-audio.pagesperso-orange.fr/Voicemeeter/
Found this amazing software for getting all sorts of different audio devices and drivers to work as I want.
Basically I think the main use for this is to get USB headset, speakers and game to work together for streaming.
Another would be multiple USB headset mess from same PC to VOIP.
Still as test I did route Interface+guitar & USB headset to output so that I can't hear my own speech, but can hear guitar just fine. Then I set that pile to output for TS3 and I could let TS3 hear my voice+guitar
Also it would be completely possible to mute guitar for voip, so that it still comes from headset? Extremely powerful software I think, also it does look nice.
This software needs to be default audio device.