Thank you Diesel911 and Alec, you are very helpful.
Alec, when you clocked it, is it just those two screws on the case or is it more involved than that?

I also come back with more data and findings, after a long drive:

At high RPMs/freeway speeds, the system is fairly stable between 13.0 and 13.5v, no matter what accessories being used.

At low speeds, however, it bounces around between 12.9v and even 15v. Then, the lights will also *sometimes* flicker rhythmically. Lastly, as I pulled into the driveway the battery light on the dash started to flicker rhythmically (this is new).

I'm pretty much condemning the alternator at this point. But, before I do. Is it even remotely possible this could be a belt issue? I'd hate to throw some parts at it and find it's really just a belt.