Few questions before building my first forge

I'm getting ready on putting my first forge together and I have a few questions hoping to get clarification or suggestions. I'm using a #20 propane tank and planning on following most of Wayne Coe's forge plans.
Using 1"thick inswool and placing 2 layers in the bottom and one in the top. And using Kast-O- Lite 3000 as my castable. And plistix as the infrared reflective. 

First question is it possible and efficient to do the whole castable as one or do I need to do multiple sections? I didn't do the cut as Wayne's instructions suggested to divide the propane tank.

Second, I'm a little confused on the angles that the burners should be place. I'm planning on doing about 2" from the center. Would that give me an appropriate angle? I never seen a forge in person and most picture show a bit more of an angle in my opinion but I could be wrong. Any suggestions?

Third, I read a few things about needing to coat and ridigized the ceramic wool from keeping the fibers from getting into the lungs. Would just using plistix help do that? Sorry I'm a little confused with this 

Fourth, I built two Frosty T burners and they seem to burn right not sure how I can tell if they will be able to do their job as their meant to do. I know they need to be place on the forge to be able to get them to tune to an ideal flame. 

And final question, when I got my parts at the store I showed the guy a picture of a T burner and the end of it which I think it's called the "Nozzle" is that also call the "flare" of the burner? I bought one that he suggested that looked closely to the picture. Do I place my burner with the nozzle/flare inside of the forge? Also if you guys can suggest a different nozzle I just bought whatever he suggested.

Thanks and please feel free to suggest anything! I just want to build a decent correct forge!
Ps. Sorry if this is repetitive to any other question asked before. I tried searching for these answers already