My final commentary for this "weird noises in the back" topic. My rear pulley definitely had some overstressed bearings resulting from my attempts at adjusting the belt alignment. Over-stressed bearings give you a very obvious creaking noise. The ratchety sound like in my video is a result of dirt/grime build up in the teeth of the pulley and belt. The service manual calls it some kind of "beading" when I came across the topic. So cleaning and lubing is your best bet for that ratchety noise if you have it.
I finally went through the belt tension reset process after buying the service manual. Talk about a painful and tedious process. For those that are curious you basically can't tweak the belt tension you have to completely reset it first by undoing the associated bolts (4 in total) to include the massive swing-arm nut. Doing this will completely loosen the belt to the point where you can take it off if you needed to.
But It's not as simple as loosening up the bolts to remove the belt tension you have actually have to loosen then re-torque certain bolts (and in a certain order) to a light setting before beginning to put an initial tension on the belt. It's crazy because it's an elaborate ritual to the point where you have to loosen the swing-arm nut then re-torque it to 195 lbs then immediately loosen it again. It's crazy but if you don't follow the 25 steps or so verbatim chances are the belt will be too tight and you will over-stress the pulley bearings like I did a couple of times getting the process/order right.
My advice to those out there thinking about adjusting the belt tension, don't do it unless you have the manual otherwise take it to a professional you can trust. I would not rely on youtube videos because I have yet to see anyone go into enough detail to get it right. Trust me, I learned this the hard way.