So, I was wondering if vacuum bagging the part once the fabric had been laid onto the tacky backing resin would help consolidate things a bit more tightly and help reduce the potential 'softening' of any subtle lines or features? I guess I'm asking if doing this will help to, in effect, de-bulk the single fabric layer and help make the skinned part a little closer to the original parts' dimensions and true form? 

Vac bagging can in fact make the job a bit harder too, for the reason that you mentioned above - it wrinkles. You can try to keep it smooth,  but if you've got a part with curves then you need excess bag. Nothing ruins a skinned part more than pinched fabric...