As far as them going in at night, let me tell you my story. I put my chicks out in the run and coop at the appropriate age, have a great setup, etc. They were doing as you said, huddling in the corner of the run every night. At first I was carrying them in every night, but they weren't catching on. I posted about it on BYC and everyone said "Don't worry, they'll catch on in a few days". Well, a few days turned into a couple of weeks. Rain or cold, they would huddle in the corner of the darn run. I posted again. I was told to lock them in the coop for a week so they'd establish it as "home". I did, although leaving them stuck in the coop was torture. Finally let them out: Right back to the corner in a pile at night. Posted here again: was told to put a light in the coop. Tried that, nothing. Was then told to put all their food in the coop, which I did. They'd go in to eat and come right back out and huddle in the run corner when bedtime came. This went on for MONTHS. Everyone kept insisting they would catch on but they were not catching on. Winter was approaching and it was getting cold and I was scared. They were getting harder to catch, I'd have to wait until they were asleep and then carry them in while they were still groggy, it was awful. I seriously wondered how the heck I was going to do this all winter, or worse *forever*. The first snowfall was a full-on snow storm, we got about 10 inches. I was panicked. The day before the storm I was out there nailing up tarps over that side of the run, trying to block snow and wind. Of course the corner they were sleeping in was right in the front, where rain would drip and snow would hit. I was a nervous wreck. The next morning I went out, very nervously to check on them. I peeled back the tarp and saw nothing. Confused, I looked around, nothing. I went inside and looked in the coop. Sure enough, there they were, all in the coop! It took ten inches of snow and wind for them to FINALLY figure out to go inside. This was probably 5-6 MONTHS after sleeping in the corner of the run. I have yet to see another story of chickens this stupid, but I always tell it when I see this question asked, because so many people say that they'll catch on "in a few days", and I just want you to know it *might* not be just a few days. I do think my chickens are a rare exception, but I just thought I would let you know. By the way, after that night they went in every single night and never slept another night out in the run, thank god.
We ended up getting them in and tonight they all got in before the door went down. They will figure it out in time.
