It looks like a good set up. I agree that the lid might be a problem. When they are that small do you even need a lid? I didn't use a lid on mine, but the sides were tall enough that they could not get out, and nothing was around that could get in. You might need one later when they get bigger, but I agree wire all the way across would be better. Don't worry about being too concerned - if you are like me there is so much I don't know, I have learned so much in the last year. You are just a responsible duck owner.