Looks good so far. Other than using the hitch bolts (which i think is great) are you going to tie it into any other locations? Like where the stock bumper mounts. I normally tie my d-rings plates and frame mounts together.
I like that double shear hinge, can never have to much strength on something like that.
Far as the ends, here's what I did on a JK bumper I built a few years ago.