Trusk'our

Hemalurgy fascinates me, mostly because of the idea that you can use it to create all kinds of crazy things, but the weaknesses tacked on to having too may spikes means that realistically, you'd probably only want a few. The coppermind says that a nicrosil spike will steal general investiture, like bio-chromatic breaths, not actual powers, like allomancy or surgebinding. My question is, what benefit is there to this? Would it act like just getting a bunch of breaths that you can't awaken with? or would it do something different?

So, this is the first time I've actually asked a question here since signing up, so if I accidentally break some kind of rule, please let me know. Hemalurgy seems to always warp the recipient of an invested spike, particularly with stolen human attributes. Since Identity is something that can be stolen via hemalurgy, I was just wondering if you were granted someone else's Identity, would your physical body change to appear more like them?