Ok... New pulley ($12 autozone) and belt ($40 napa) and I'm up and running again. Check engine light was still on after the repair but went mysteriously out after 2 minutes of driving. I also changed out the PCV and fuel filter while I had it in the garage. Don't know if those could have been the cause for the check engine light or not. Anyway, tingy vibration sound still exists at ~2500 RPMs. Hoping to track it down this weekend...