Spent yesterday and this morning looking at it again. To get it to work with the X4rsb I have had to use the SBus converter that I was going to use for something else.
It seems that while the Flight Controller was happy with the signals coming directly out of the receiver the OSD did not like them. So while I can use the direct output to control the quad it will not allow me to enter even enter the setup screens without the converter connected. So have left the converter on as getting to the settings without having to have a computer with me was one of the main reasons for buying it.
I figured out that the throttle back issue was due to the flight mode. In Acro I could throttle back without the converter.
Thanks for all your help. I now need to put the props back on it and see how it flys hopefully it will stop raining.