I looked through all of this and I too like this horse a lot. I wish she had inherited more of her Saddlebred's bone but she did not. Her back is nice and short and strong, but she is going to be a bit stiff and require a lot of work to get her to stretch her topline and get her hind end under herself to lighten her front end. She CAN do that (physically) so I would work on that stretching!
Her legs are a bit light and her hocks may not hold up for the years it takes to develop at the higher levels, though her overall build begs one to try for it.
A light (small in stature, height-wise), athletic, rider could probably take this horse all the way to Grand Prix if she has the mind for it (the horse, not the rider LOL).