I would candle the 14 at the end of day 14 and only keep the one's that are fertile then remove 2 of the rails, should give plenty of space to hatch those in. I would put some kind of divider (maybe a piece of cardboard) between them and the rails so that when they hatch they cant get smashed...
I put mine in the incubator when I receive them and wait for 24 hours before I start turning them. My last hatch I had 120 of 138 hatch, 86%. Eggs where shipped from Pennsylvania to Texas.
You might want to check out kingshatchery on ebay. he is located in Pennsylvania, might be close to you. I have purchased from him several times with great results. My last order was for 110 eggs, he sent 140 had 2 that were broke and I hatched 120 out of the 138, 86% not to bad for shipped eggs.
It depends, what is the temperature under it at ground level? Move it up or down to get 95 degrees under it. I would move the water and food closer to the light also. What are you feeding them?
I cull any chick that has foot, leg or neck problems because I'm planning on selling them. If these are just pets for you and they can get around then I'd let them live.
Browns have a white recessive gene. Some of my birds have white on their wings and if you hatch enough you will sometime get one that is all white. Including a picture of a couple that are from my brown birds that will be all white.