Is a damaged BB7 inner caliper pin dangerous?
I think the only purpose of the pin is to retain the pad. So if you can convince yourself that the damaged pin isn't preventing the pad from sitting cleanly agains the "piston" and that it is prevented from dropping out, then I would be inclined to think you're ok.

I've seen instructions for rebuilding BB-7 calipers, which makes me think that parts might be available – at least in some markets. The SRAM/Avid number for the "internals kit" is A150080A and they appear to be available, I found links to the kit at shops in the UK, in the US Amazon lists the item, but doesn't have stock. In any case a whole new brake assembly isn't too expensive (considering that you get a set of pads and a disk as part of the deal), so if you have any doubts I'd just go ahead and replace the caliper (or see if you can get parts).