I have 2 shelves and 2 roost's in my coop. the girls don't use the roost's at all should I remove the top shelf (which they like the best) and make it a roost? or just leave it as is and let them be on the shelf.
Unless you have a specific reason for not wanting them to roost on the shelves I don't see how it matters. My Silkies like to roost on my shelves but the rest of mine use the roosts. You just don't want them roosting in the nest boxes.
I have both. The roost is over the shelf and I use the shelf as a dropping board. My girls sleep on both at night. I just make sure the shelf is cleaned before bedtime so they won't sleep in poo. I think the shelf comes in handy in the winter so they can double up, snuggle and stay warm. It's a personal preference. It works out great for me.
I too have a roost over a shelf, and they all huddle on the roost at night - including the rooster. Then again, he does think the rabbit is a chicken