Org allows you to set a wider range of priorities -- so should BeOrg. I find the usual 3 priorities (A, B, & C) to be too restrictive and generally increase to A-E, but I could see people wanting even more flexibility -- even on a per-file basis. Can you do something about that?
Yes, sounds like a good idea. The current range of A - F was a little arbitrary. I will look to allow users to customise this via a Scheme variable whilst keeping the current default for most users.
This will be in 2.11.2 where you can redefine a Scheme variable org-priorities. This will likely be available later this week.