I am with Patty on this one. I use that technique on my own horses and client's horses and have not had a horse become injured from trauma. It is an effectice and appropriate way to correct flare.
Over all I think all of the hoof photos that you have posted look fantastic. There is no critical problems you need to address you just need to maintain what are already good looking feet :)
That is "not" the appropriate way to trim a hoof!