Given that I'm going skimmerless, do you think I at least need a 10-gallon refuge, or can I get away with 5.5-gallons?

Also given that it is a small tank, 14" tall, I'm planning the following: 2-inches Miracle Mud on the bottom, 4-inches sugar-fine sand, 2-inches crushed shell on top.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.