so I've been back to Windows, only come to find Zorin has spoiled me too much and now I clean installed Zorin again Just FYI.
It also seems like this is a general issue with my (audio) system, as the issues still go on after a clean install (Like wiping every bit of the previous installations and re-install it), but to answer your question precisely: No, I don't use a seperate soundcard, but my motherboard has some sound settings, gonna check those later
Your changing symptoms remind me of about a year ago when my hard drive was starting to fail. Things would be working fine then one or another weird things would happen. Just a thought.