Oh and I remembered the simple conclusion I came to with the help of other suggestions here... Play vid/streaming audio on my internet laptop. Use laptop output and adapters/cables to feed directly to the multi ins on my Scarlett interface which is of course connected to my DAW. That way I don't have to fiddle faddle with any weird routing or software/resource nonsense AND I can use the input trims on the interface to attenuate levels as needed... without feedback loops or the like either.
Obviously this requires a second computer in the room and some extra cabling gack but I'd imagine most of us have secondary systems around and the adapters/cabling is pretty cheap (1/8" stereo splitter to two 1/4" mono).
Sorry if I'm being obnoxiously obvious... but that's how I roll. Path of least resistance, leaf in a stream... and all that rot. Cheers.