How much a problem is the smell, and whether that smell travels that distance.
If you can keep your coop and run dry smell should not be an issue. Well-drained is a great start on that but you may need to manage the poop so it doesn't build up too much. If it builds up it can stay wet.
Will the fact that they are able to be out of the coop/run most of the time cut down on their smell?
Yes. They poop a lot wherever they are. The more that is spread out the less likely it is to build up and smell. At night on the roost they are not moving so poop can build up. You'll probably have to manage that.
The others make some good points about where they will go and the damage they can do. The only way to control that if it becomes a problem is to either fence the chickens in or fence them out. For some people it's not a problem. I fenced in my garden, but that was for deer as much as the chickens. It was necessary for both.
I find that each flock has its own dynamics. When I change a few flock members, especially the more dominant ones, flock behavior can change. Some flocks stick pretty close to home. Others can roam a long way, several hundred feet. Some stay under cover more than others. Some stay in one flock, others split into sub-flocks and cliques. About the only thing consistent with chicken behaviors is that they are inconsistent. But that can make them a lot of fun to watch.
If you can keep your coop and run dry smell should not be an issue. Well-drained is a great start on that but you may need to manage the poop so it doesn't build up too much. If it builds up it can stay wet.
Will the fact that they are able to be out of the coop/run most of the time cut down on their smell?
Yes. They poop a lot wherever they are. The more that is spread out the less likely it is to build up and smell. At night on the roost they are not moving so poop can build up. You'll probably have to manage that.
The others make some good points about where they will go and the damage they can do. The only way to control that if it becomes a problem is to either fence the chickens in or fence them out. For some people it's not a problem. I fenced in my garden, but that was for deer as much as the chickens. It was necessary for both.
I find that each flock has its own dynamics. When I change a few flock members, especially the more dominant ones, flock behavior can change. Some flocks stick pretty close to home. Others can roam a long way, several hundred feet. Some stay under cover more than others. Some stay in one flock, others split into sub-flocks and cliques. About the only thing consistent with chicken behaviors is that they are inconsistent. But that can make them a lot of fun to watch.