I get that "ewww,she's dragging her fingernails on the blackboard"
feeling when I hear people wanting to mod one of their knives.
However,I am very surprised by much of what they accomplish,
fantastic stuff some do.
Me,I have to stay away from attempting anything like that for
now...Maybe when I get more experience convexing an edge first.

It does sound like a good idea,that extra edge for a ferro rod,
but I have found that a sharp 90 degree edge works fine.
Cutting Barbed Wire,dunno,never tried it,I would use
wire cutters,unless it was an emergency.
(in which case I would borrow a friends knife to cut it)

Good luck and let us know what you do.
Lots of pics are required. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />