Is there a way to set the scope of an effect other than manually dragging it in the timespace on a clip by clip basis? For instance if I create a Colour Grade layer for 10 shots and then decide I want to move it up 5 layers how would that be achieved in one go or would it have to be done manually for each clip?

As rob.gordon suggested before, you can select all the grade clips, lock them (L) and drag them up or down. That should adjust the scope coverage for all the clips. Then, you can unlock them.

A

You can also select the files you want to group, use the Macro "Group Segments", which will group them individually, and set the color grade for those groups selected. 

Cheers

Cristóbal