Great questions and I'm going to do my best to answer them for you. Keep in mind that there are a lot of variables. It's almost like asking how much power do I need for solar....depends on what your area is and how much you are willing to live without.
One factor to keep in mind is that we pasture raise ours and don't keep them in cages, so they have access to other protein sources regularly. So, here goes:

Live weight at processing is ~16 ounces (1 lb.)
Carcass is ~ .6 ounces

(Variable) The feed we have access to is 28% game bird feed @ ~ $17 per 50 lb. bag from our local feed store by Nutrena. We don't have any mills or any other options in our area, so once again, this is a big variable if it is available in your area, or if it is even available organic. We do not have the option for organic.
(Variable if on pasture) - We fed ~ .1-.15 pounds of grain per bird per day = 8.4 lbs / bird for 8 weeks
(Variable) 8 - 10 weeks grow out

A few key points:
*The females were already laying eggs when we processed them at 8 weeks. (if you didn't know, quail lay once a day like chickens and start at 8 weeks, therefore making it a very sustainable source since they can start reproducing at the same age of maturity)
*Feed ratios would change depending on where we put them on the grass. Since they were in a tractor, their grass was limited to what was inside the tractor, therefore affecting what was available to them. Seed and bug availability changed.
*We have only done this with pasture-raised birds, so the cage-side of the equation, we have nothing to compare to, although I would assume it's comparable to chickens.

Through watching your blogs, I know you know what you pay etc for your own chicken feed, feed conversions, etc, so I'm not going to compare our chickens. This is our first time doing this many birds at once, so our numbers might be slightly skewed due to waste etc, but that's about all I can give you at this point. I hope this helps!