Your doing GREAT!!
It sounds like you know what your doing too. The cardboard looking wax is capped brood. That's exactly what I did too was move a frame (or 2) up to the next box with the nurse bees still on them.... After I did that I went back in a week and WOW they had drawn out 3 more frames of brood and I saw the queen up in the top box making baby's!!
Did you remove the paper between the boxes if you did GREAT if not take care of that. The difference of cells is easy..... what you saw that looked like cardboard was indeed worker cells after a while you will see some cells that look like bullets (they will be sticking up about a 1/8 inch more than the other cells they are droan cells and you cant miss the queen cell it looks like a peanut!!
You should be fine leaving them alone for a few weeks plus spraying the frames with sugar water should be fine they did it on their own when I moved up one of their frames.
Again you are doing GREAT!!!
Isn't beekeeping FUN!!!!!!