If you are turning them by hand, laying them on their sides is fine. You only need to have the pointy ends down when using a turner. Were you staggering nights? Every night, you should have the egg sitting on a different side. E.g. One side has a "I" on it and other has an "O" in it: night#1...
Also, if you don't see any dark spots in the eggs they most likely never started to form, so don't worry. That one dark one, though.... If you are absolutely sure it will not hatch, you could open it and take a picture of the result. I know, sad to think about....
Okay. Next time, let your eggs sit pointy end down in an empty egg carton for about 24 hours. That way the air bubble will have a chance to move to its natrual spot, and the yolk can settle. Also, when they are in the incubator they need to go pointy end down if you have a turner.
Yes, there is a chance that the eggs were "dead" before you even started. How long did you wait to put them into the incubator after they were delivered to you?
Shipped eggs have no promises of hatching. Is your incubator at about 98.5 degrees? what is your humidity? Also, on day 18 did you stop turning the eggs and decrease temp by 1 degree?
If the eggs don't hatch, you can't do anything to make them hatch.