The end of my curve is not in the correct place. It terminatesat the end of MCH_ArmSpline.010 instead of MCH_ArmSegment.00...

This could be down to the way in which you've applied the Hook modifiers - which I admit, is horribly unintuitive at first, because there's not a whole lot of visual feedback. Although this reply is probably too late for you (what with your post being a year old), hopefully this will help anyone running into the same problem (you might also want to delete any existing hook modifiers on your curve, so that you can start this process from scratch): The trick to it is to know that your armature silently 'remembers' which is the active bone, even when you're in Object mode. 1) select one of the bones to which you wish to hook your curve (in pose or edit mode). 2) switch back to Object mode. 3) with only your armature/rig selected, shift-select your curve. You should now have both your armature AND your curve selected, but your curve should be the active object (brighter orange). Don't worry if you mess up your selection at all - just keep trying until it's correct - and use the Outliner panel to help if you're struggling to select the correct items (fiddling with your Object selection won't mess up the active bone you selected while in pose/edit mode). 4) with your armature and curve selected, with the curve as the active object, tab into edit mode. [Remember: the armature is still remembering the last active bone, even though you're now editing the curve] Now select the vertex on your curve that you wish to hook to the active bone. 5) press Ctrl+H and select 'Hook to Selected Object Bone'. If in doubt, you can play with the pose of your bones at this stage to make sure that your curve is correctly hooked. 6) repeat steps 1-5 for each bone/curve-vertex you need to hook together. Hope that helps someone!