As far as we are aware, when IsReadOnly is set to true and IsSelectionEnabled - to false, the only elements that can be moved are tables when selected with the table adorner.
You can work around this by removing the UI layer
responsible for table movement like this:
MyCustomUILayerBuilder : UILayersBuilder
I hope this helps! If you are observing different results on your end or are having other difficulties, please let us know.