Regarding most of your questions, remember, if 99 people on this board are of one opinion, and your local building inspector disagrees, guess which one counts? my opinion in general is that its sounds like a neat idea, different look, view preserving. certainly there are materials strong enough, expense might become a factor though. And some plastics go very many years w/o yellowing. or how about glass? widely used for years in mezzanine railings like at shopping malls.