I have the low end 16/3 Business Class Starter package, and your current 500GB usage would be a light usage month for me (I don't do any bit-torrent activity, and very little video streaming , but I do operate public servers). I seriously doubt that any business class customer (even on the low end package) would be harassed by Comcast for a steady multi-TB usage pattern -- and all that would happen if Comcast did object to your usage, would be to migrate you to a more expensive plan.
The only thing Comcast "monitors" for business class customers is the "content" of their usage -- and even then, unless it matched their algorithms for spam or botnet activity (or perhaps child porn distribution), they would only intervene if some outside party registered a complaint. As an example, my »
portscan.dcs-net.net site has in the past been subject to "abuse" investigations by AT&T and Covad (when they were my ISP), but I have never been bothered by Comcast for operating that site).