re: We need a shuttle.
Other than the seemingly rare occasions when we want to return something hefty from orbit (a satellite for repair, for example), what do we really need a shuttle for?
And if we do need such capability, would it make sense to develop an unmnanned return module that could be flown up with the CEV? The crew secures the cargo in the module hold and sends it down.
(If I've made an obvious omissions or stupid assumptions, be gentle with me.)