I spent most of today setting up the pose sliders for Rose’s eyes, but I’d say the results are worth it – 
Yesterday I noted that it is much easier to understand how a rig works by rebuilding it. Something else I learned today, is that a character’s skin solution isn’t set in stone when you start rigging. As you’re setting up the rig, you may find it necessary to add helper joints to assist the deformation. In this case, Rose’s eye corners were sinking into her cheeks when I pull the slider down. Some extra joints help to pull the surrounding areas down, to even things out.
I’ve also added something I think the Malcolm rig was lacking: having the eyes affect the surrounding mesh as they rotate –
One other trick I’m trying out might be overkill – rather than using a wrap deformer to attach the eyebrows, I’m using a series of joints that are constrained to the surface. The main advantage to how I’ve set it up, is I can easily pull the eyebrow away from the surface for a more cartoony effect. I suppose I could have gotten the same effect by applying a cluster to the wrap-deformed brows, but I’m sure this technique may have its uses elsewhere…