I'm assuming the concerns were unwarranted if the pulleys run fine, though I understand the cause for concern!

Some additional info:

When I put my ear toward the top of the pulley, I don't hear much. But as soon as I put it up next to the front of the pulley (the bolt), the scraping noise becomes quite clear indeed. Bearing?

I guess I will have to install the stock pulley again and listen, then install the C3 and see if it's abnormal.

Will keep everyone posted.