Loud squeezing sound

If I had to guess...with what info given...it sounds to me like the clutch is not fully engaging. A clutch slip can make the clutch squeal too...like a wounded bird.

It just made me think slipping clutch when he said,..."now the clutch doesn't even have to be pulled to rotate the wheel.... dumping clutch makes horrible squeal." If the engine compression is high enough on a misadjusted clutch or related other issue you will get that sound. The pads slip instead of the engine turning over.
I would agree, the whole issue is with the clutch and/or cable. Can you post a picture of the left side of your engine?