I have suggested sending Gus to a professional for one month.  She is such a smart girl and I believe that a month would be plenty of time for her to learn some ground manners and a basic work ethic.  Hopefully she would also begin to realize that squashing fences is not a good thing.  After that, I think she would be very reasonable to work with and would progress really fast.  She has a sweet and mostly cooperative disposition.  She has simply been trained for too long to evade whatever she doesn’t want to do.
He does not want to invest more $ in her for training, so she will be traded at the first opportunity.

Thus ends the saga of Gussie, the Big Horse Who Could Have.