There isn't currently a way in ArtRage 2.2 to offset layers directly, but there is a workaround.
Export your layer as a *.png file.
Create a new layer.
Load the png as a tracing image.
Using the tracing tools, position your tracing overlay where you want.
Choose 'Convert tracing image to paint' which will put it back as paint on your layer.
It's not perfect - when you exported the layer as a PNG it lost the depth of paint and information to make the paint work like physical paint.
But it still would look the same.
Super Secret hint... The next version of ArtRage is in Beta testing, and it will have a better way of moving the contents of your layers around.
Due out very soon now!
AndyRage's mantra for graphics engine code:
"Sure - how hard can it be?"