Letting my chickens/roosters out to run free

The cats shouldn't be a problem but Traffic and the dog defiantly would be. Also I would not advise free ranging them in a area designated for your children. Yes they will come back home to roost but they need to be trained for that.

Kids can be a concern and if the kids are old enough train THEM to stay away from coop area and ONLY in the picketed part. Chickens MAY jump over picket fence but.. Depends on distance from road,neighbors, your control over your dog(my dogs were raised around chix,etc and won't bother them and they know I am boss) and I PRAY your barn cats are spayed/neutered as mine are. I don't know the issues with chicken poop.... unless your chickens have worms,disease(which a well tended flock shouldn't) then it WOULD be a concern. I have had chickens almost 10 yrs. and didn't have worms/parasites until I started neglecting cleaning of coop so probably MY mistake. Learned the hard way!! My son was 8 when I first got chix so he knew how to respect the chicken area by that age.(and scrub his hands etc.!) OH forgot-the think I ADORE about chickens is they learn QUICK to come into the shed at night.

We have a backyard flock, so the yard is shared between my two children, three cats and five chickens.  The kids have been taught since the beginning to wash hands after touching the girls and to be careful around the poop.  We periodically go around and spray off the walkways and pick up the bigger poos off the grass.  They are my pets and as such, I have to pick up poop.  No big deal.  Also, a section of our fence is only about 4.5 ft tall and I have not seen the girls even attempt to fly over.  Just putting in our experience for you to consider.

Yes, your chickens will be much happier and healthier if they are allowed to run around for part of the day. They're big enough that the barn cats shouldn't bother them. If the dog has not been trained to leave the chickens alone, tie it up or put it in the house when the chickens are out. The chickens will return to their coop to roost for the evening without training. They've been there long enough now to think of it as home. They will jump up on and fly out of your picket fence. Leave that for the kids. BTW, a little dirt, manure and germs are good for kids. Honest. If you're close to the road, you may want to put some sort of fencing up to keep them off the road. If you're a ways back, they may not roam that far anyway.