Why not put a rear view camera on the back of the trailer to take care of the 'seeing around the trailer' issue? The width of the Tacoma with mirrors is nearly the width of the casita. You should be able to see whatever is beside the trailer and with the camera you can see what is behind it better than with a full size vehicle.
I have a camera on the back of my trailer and love it. Especially like seeing when someone comes up racing behind me on the highway. That is nice to know if I am planning on changing lanes. Would never see that w/o camera.