I'm sorry, but I really don't see where the "nothing but my bones" line was that horrible. I've heard people talk like that before, and I think I might have heard that exact saying before.
Ditto. The "sawbones" controversy aside, it sounds perfectly conversational to me.
"Ohmigod. You're nothing but skin and bones."
"He skinned me alive in poker last night."
"I'm down to bare bones."
That's just how people talk.
It's also worth noting that the scene is set 243 years in the future. It's probable that people then will be using slang and idioms that would sound unnatural and awkward to our ears, just as something like "My bad" or "Awesomesauce" would sound bizarre to someone from the 18th century. (Heck, from the 20th century. I was violently resistant to "My bad" when it came along. It infuriated me, hearing an adjective used as a noun like that, particularly when there were already perfectly serviceable alternatives like "I'm sorry" or "My mistake" or "Excuse me." "Your bad
what???" I always wanted to cry. I've grudgingly learned to tolerate it since it seems to have had staying power, but don't expect to ever hear me using it.)