I have a Mac Pro and my Bold doesn't seem to charge over USB. Is that typical? If not what could be the problem?

You need to install PocketMac for the BB.

Without drivers installed on any computer (Mac or PC) a BB will not charge.

Also the Bold seems to like to be plugged directly into the PC. It will not charge on my powered usb hub or the usb ports on the front of my PC.

I charge my Bold on an unpowered hub connected to my PC ok.

I've noticed that the Bold seems to charge more quickly when I use the new USB cable rather than one of the tangle of old one's I have on my desk. FWIW.