when the installer has finished the installation, request for
him to show you fully the operation of the system,
if he expects you to move or adjust manually anything at the dish, i would advise you to say that this is not what you have paid for. 1500 should you a dual drive dish system. you should also not have to change the cables at the echostar either.
also check out the
http://www.jaeger.com.tw/menu_framset.htm web site and review the 1224 mount so that you gain an understanding of what a dual mount should look like.
You will need still a motorised dish for both elevation as well as rotation. This is due to the orbital path of the Eutelsat 11F3 satellite.
With a 1.2 the gable end with the wall thickness that you specify should be ok but please ensure that the wall loading is evenly distrubuted, from the mounting and not just in one small area.
regards
Old satellite