You're on the right track, but you could also just look at 2B and HR rates to gauge the quality of contact allowed.I'd think that SLG% on BIP would be a very telling stat. When a guy DOES gets hit, is he giving up dribblers or rockets. It'd also give you some idea of how far a high K guy might drop as his K/9 began to come down.
I'd sort of assume somebody already has thought of this.
GL