With years of having chickens, I have tried free range, but for me it did not work. I was a nervous wreck the whole time and when dark started to creep up, I ended up having to coral my 8 ducks and thirty something chickens. The ducks were not that hard as most of them are flightless large pekins, and the others sinply followed them. Now, the chickens, were another story. My rooster, Maple, (we have a love hate relationship lol) obliged me in taking about five or six of the hens inside with him. The hardest were my other two roosters. They are constantly picked on by other chickens, there names are Clucksworth (hint: my name on BYC), and Mr. Ugly (we had a Mrs. Ugly but she unfortunately passed away this past winter.). Needless to say, I will never again allow my chickens to free range.
But moving on to your questions, (sorry if I got a little sidetracked on my disaster.). They will poop in the uard just as they would in the run. I have had family members who have had troubles with their chickens flying in their cars, and my uncle had a hen who flew in an open window and made a nest in his backseat! And I agree with previous posts about them high tailing it to the porch! They should be fine otherwise.