My question: Is there a configuration setting in CB GroupJive that allows the photo (and ideally file/video) upload directory to be changed to a custom path?
There's no such feature at this time.
The current plan is when CB GroupJive is redesigned into a standalone Joomla extension it won't use the images folder anymore, but the new "files" folder where user file storage is designated (implemented in Joomla 5.0) by default with support for overriding the path. At that point it'll be made compatible with Joomla's file system adapters so you'd be able to use an adapter to store the images externally and retrieve them externally.
without resorting to filesystem symlinks.
Is there a reason why? A sysmlink of the /comprofiler/cbgroupjivephoto directory should immediately solve this.