Are you implying that it's impossible to modify or create enzymes that aren't denatured at (what was it? 350c?)? Because that appears to be what you're saying is completely unrealistic.
I don't get where I would have said that.
Both. Explaining is good but links are best.
Well, I'm not good enough at link-fu to link paper books, so I'll just explain.
Brain size: Should be obvious. Smaller means smaller head. To a point, we can just keep more neotenic proportions, but once we get shorter than a meter or so we'll have issues.
Coordination: Depending on how much of this is learned and how much is instinctual (we really don't know), the much smaller mass and size would screw up coordination. Just to provide scale: They could probably jump as far as normal humans. Not proportionately as far,
as far. Oh, yeah, the nerve signals are going a lot faster. If there's an instinctual component, the small people are going to be clumsy.
Senses: Sight would be negatively affected due to smaller pupils. Our pupils are massively larger than visible waves of light, so interference from the edges of the pupil would be minimal, but that would get more severe if we made the pupils smaller. As for hearing, the eardrum's reduction in size would change sounds roughly the same as changes in the voice box would change the voice. I don't remember how small it was, but one book I read suggested that it would render the small guy effectively blind, deaf, and dumb.
General: Proportions would need to be adjusted across the board, most likely.
Those come to mind first.
I contend that incorporating carbon fiber into our bones is perfectly feasible with advanced genetic manipulation, and assuming that the rule of awesome is in effect I challenge you to explain why it isn't.
Assuming it is, there's no point to this argument.
Assuming it's not, how would the carbon fiber even be produced?
Who says? Maybe in this hyper advanced society they've already discover the Avatar carbon fiber gene. And again, I contend it's not impossible. Therefore it's possible. Therefore it might be worth a try in a forum game where we don't have to worry about actually writing the code ourselves.
And maybe they've made unicorns that poop puppies.
More seriously, that same argument could be made for anything. Maybe it's technically possible for us to make that, but it sure ain't happening because we don't know how. You're asking a monkey to make a copy of Shakespeare's works without having read one.