2D sprite animation process ?

Rigging a 2D sprite is great for generating character animations but I have an issue. I want to do animations such as an idle where the character's chest swells and shrinks, or a run animation where the shoulders and hips stretch and shrink along the X axis for a 3D effect. The problem is that after rigging my legs and arms are children of torso and any changes I make to the parent also happens in the children.
I tried un-parenting first, scaling the parent, then reattaching the kids but they immediately snapped to reflect the parent's edit. My only solution was to run separate bone rigs on the torso, head, each arm and each leg but then, of course, you lose chained translations such as rotating the torso and nothing else moves. Likewise you lose pivots as your legs, arms, etc are no longer affixed to the body and as you rotate them to new key frame positions they pivot crazily and must be hand positioned for every key. That works but ugh, there has to be a better way?
Honestly, for something like scaling, I'd think there would be an option to only change the parent through edits? All the children would need to do behind the scenes is scale their attachment coords accordingly.