I am working hard on getting the coopaloop finished up and we will be tackling the door to th run next. So.... 1. How big does the opening need to be? 2. How high of a ramp would be most desirable for my young chickens? 3. Is it ok to put hay in the run, one part of it is susceptible to mud and thought hay would be nicer for them. 4. Food indoors or out? 5. What kind of lighting is ok in the coop? 6. I see they like sand, can I just do a kiddie pool of sand for them instead of the whole run? tHank you!!!!!!