I was looking for this too! currently i collapse the node and then drag it. Sometimes when the node is open I end up moving just one item and I have to sort everything out.
I agree that a native solution would be best. I am also sure that JavaScrip can do this. Until we have either of those, here are two efficient ways to do what you want just with the keyboard (no mousing or dragging involved):
It should be that anytime you drag an item by it’s handle it will bring along all dependent items. This is not the case when you use keyboard shortcuts to move item up/down, but dragging by handle should always do this. If it doesn’t it’s a bug case that I’d like to know about.