As much stuff as you can get in the compost the better, but you need to make sure you add some dry matter here and there. Roughage if you will, grass clippings, straw, pine chips, pine needles...so on and so forth. You can look up composting formulas, but really you want it to be at least 1/2 roughage, 1/4 dirt and the other 1/4 everything else, poo, veggie scraps, so on and so forth. Try not to add anything salty, oily, or meaty and that will keep most things from rummaging in your compost. You will have the best compost ever. We compost all of our chicken bedding, but the idea of having the compost pile right under the coop is awesome. If you have ever turned over a large compost pile when it is really really cold outside and saw it steaming you know how much heat a good going pile can generate. In Summer the compost pile won't really add that much heat because the ambient heat is usually enough so the compost won't heat up as much, but it could potentially make it warmer in winter. But compost piles work the best at right around 100 degrees F. So in winter the bacteria and organisms work hard making it warm, and when it is warm out they don't have to work so hard...but the heat is what breaks down all the matter that is in the pile. Just make sure you can turn the pile pretty often to keep everything bopping right along. You can also compost your dryer lint and paper and cardboard. It falls into the roughage category...like shredded newspapers are great for starting. You'll have to look up the actual ratios, actually composting is really interesting to me, so give it a look and see what you think and how you might make it work, but having wire under the roosts is very possibly the best idea ever, because as soon as chickens fall asleep they seem to poo all night long by the looks of the areas right under the roosts. I wish I could incorporate something like this with our coop, but our coop is the top floor of a 2 story garage thing...so the poo would have to fall into the garage, and I'm just not for that...so we have to sweep all the hay out the door and then gather it up and pile it in the proper place...