If it is totally secure, you can leave the coop door open for them but....
- .I can't tell from your picture what the fencing is. If it is chicken wire, that won't be strong enough. If it is fencing, how large are the openings of the fencing/mesh/whatever it is?
- not sure how the fencing is fastened to the posts - could a coon rip it off?
- Not sure if the "ceiling" of the run will support full grown coons, assuming you have those in your neck of the woods ( is there anywhere free of coons?)
- how about critters digging under?
You might scan the predators threads to see how predators have accessed other people's chickens. Everyone has local predators, whether they are fox, bear, coyote, coons, weasels, mink, dogs, dogs, dogs, hawks, owls,.....I'm sure I'm forgetting some! oh yeah, skunks. Those are the ones I have in my area. Anyway, figure out what yours are and then for each of them, see now they could or couldn't get into the run or coop.
X2 - I guess I would just ask how strong and can something dig? I don't have to really worry about either of those because I have two dogs that don't allow anything to live once it crosses into our fence. That said, our dogs would also kill the chickens and ducks if they were out running around, but they don't try to get through our run and they don't try to dig either. The most they do is bark at them when mating is going on because there's all this commotion in the coop - LOL. One of our dogs got 3 big skunks last summer and somehow did it without getting sprayed! If I didn't have them, I would re-think my run more as I would be worried about something digging. We do have raccoons in the area (about 20 miles away) but I've NEVER seen one here - we are out on the prairie and they stick to the more city area, away from us, where there is trees, rocks, and a creek. My biggest threat I think is hawks, skunks, and coyotes.Oh, and snakes - which is why I did hardware cloth on the bottom just in case a snake snuck past my dogs, which I doubt because half the time I am rescuing king snakes from them and letting them go across the street into the field. I love having the king snakes around because they kill the rattlers. I have the top secure from hawks - which you really have to make sure! I'm amazed about how many friends of mine had hawks get in and then couldn't find their way out. I did not dig down and place fencing underground to deter diggers but I might consider that too if I didn't have the dogs. I don't have opossums, weasels, or other strange creatures that can find little holes and get in so I'm glad about that! I feel sorry for people that have to deal with bears! Yikes!