Just an update. I decided that before the squeaking starts again, I would replace the rollers and after checking the belt... I did that too. Buttoned it up about an hour ago and all the benchmarks are good... almost as quiet as a mouse. Followed all the normal guidelines here about cleaning the shafts and such. I also removed the idler roller and cleaned that... didn't replace the roller there, but I got rid of all the crud, lint, and other junk then I simply surfaced it with a dab of lubriplate white high temp lithium grease and wiped off the excess with my finger before putting the idler roller back on.
The belt was cracked quite a bit so even though it hadn't broken, I figured why not?
I like that idea of hooking up a door chime to that annoying buzzer. Is the buzzer located on a circuit board or is it pigtailed and buried someplace in the dash?