Would be very nice
I think this is what you want?
I am Ctrl+Clicking in this clip to rotate only the Gumball.
With the Gumball off, drag any sub-object and press Shift to snap to Guides. Smart Track helps to snap in reference to other objects.
With the Gumball on, you can use SmartTrack without having to press Shift.
Make sure your Gumball is set to Snappy Dragging.
Here are my settings for Smart Track and Guides:
Options, Modeling Aids: set an angle at which you want the guides to show up.