Shredding belts.

I think with you boiling the fluid etc that your ps pump.may be cooked. Check endplay AND good alignment on ps pump pulley. My ps pump had end play after I rebuilt it. Had to press on pulley to exact same spot(pain in the arse 2nd time around lol)
Also check new waterpump where the mount bosses are for all the brackets. Compare to your old water pump. I've had a new one off. Had to grind bosses down.
Good luck.