Because... I think I just did it. It was driving me nuts so I just poked at it till I got it to work. I have to do some more "robust" testing but so far it seems to work.
It is just a new version of the bone select tool. But the delete bone function stores the old ID's and offsets the constraint ID's by 1 if the old number is less than the deleted bone's ID...
<sigh> my goodness I lost track already...
Anyway it seems to work. I will post it when I am sure there are no big problems. Best bet I think is to make it a "custom" bone deletion tool for special situations. At the moment it doesn't handle deleting bones with children which is fine by me.
I will create a new script with custom icons etc etc and post it later.
Finally I can delete bones! I haven't been able to delete bones in ages because of all my constraints. I kept extras in a nice pile off to the side and reused them.
-vern