Okay, so, I caught my anti-virus/internet security software (Comodo) randomly hogging 60% of my cpu. It didn't do it all the time, but it insidiously wouldn't actually shutdown, so I uninstalled it and switched to Kaspersky.
Now while youtube/audio sources are running, my CPU utilization stays around 15-30%.
So everyone might have to check your anti-virus/internet security software interaction's with Opera.
But the memory usage of Opera has increased so i think I turned off/on a couple flags I shouldn't have and have to play around with that.