I beg to differ about the sand issue. I've never heard of sand being associated with lead poisoning, but I suppose it's possible if there happens to be lead in the soil around your place from old buildings. However, clean builders sand isn't going to harm chickens. I've been using it in my run for eight years, and my chicks are being brooded on it right this minute.
When I installed my chicks, one day old, in their outdoor brooding pen, they went nuts eating sand, ignoring their fermented feed. This was far from being my first chicks brooded on sand, so I knew this was going to be short-lived, and it was. They suffered no ill effects and began eating their feed the next day. They are now two weeks old and doing just great. I didn't let the grit they had ingested go to waste, either. They got introduced to meal worms on their third day, another "rule" I happily break. Chicks know how much grit they need, and consume it. Sand is a handy substitute for store bought grit.
I will be transitioning them to the coop in another two weeks. All I do is move them in one night, and in the morning, I open the pop hole and show them how to come out into the run. The first night after that, I need to teach them to go into the coop to sleep. I get inside the coop with a flash light and coax them inside with their favorite treat - meal worms.
The second night, I need to coax them in again, but by the third night, they usually go in on their own. My chicks don't need to be cooped up since I teach them to go in and out. It's easy, doesn't take long, and they are putting themselves in the coop by age five weeks, and roosting, too.