My favorite chicken setup over the years has been a walk-in coop attached to a large covered run. This provides birds with ample indoor and outdoors space to be fully protected in, and allows you to open their pen and let them free-range if/when desired.
I've found that chicken stink has more to do with diet than any other factor. Feeding store-bought cooked pelleted feed
is a fast tract to rancid, stinky excessive poops. I refuse to feed cooked pellets. My preference is whole and/or cracked grains, mixed to a high-protein ratio with free-choice minerals. Fermenting it in the summer is an awesome way to stretch feed even farther. Fermentation in winter is nice too, but you need to be able to do it indoors which we can't, so just a summer thing now.
I once had a 7.5x12' walk-in coop attached to a 12x20' chainlink run. At the most I had 50~ birds in this setup and there was no smell or stink in the coop. I use deep litter to help with smell and mites. In that setup, I took out half the soiled bedding twice a year; spring and fall, and each time added half a bale of straw. I rotated the pile with a hoe maybe once a month. Super economical and very clean and low-odor. The litter was about 2' deep, deepest under the perches. I decorate my outdoor runs with a few essentials; perches, outdoor lay boxes, a covered year-round dust bath, small brush branch piles, things to hide in/run around, and stimulation like litter to scratch through, etc. Birds can spread out and up remarkably well and it was often hard to tell I had 50 birds in there. I penned them up in the spring to let the forage grow then let them free-range later on. It's also nice to train them to a call when you feed grain, so if they're out free-ranging they should come running back home! With that method, you gotta withhold any grain until you're ready to pen them all up, so they're good and eager for their daily ration of high-calorie grains!
Also, I've had in excess of 30 or 40 hens dedicatedly use 2 or 3 nest boxes. I used to offer 1 per hen but screw that, they don't care. They all want the same one or two boxes! For 8 hens you wouldn't need more than 3 or 4 boxes, liberally, and they'll still probably only use 1 of those. My favorite nest box option is an old night stand or wooden desk end; the kinds with 2 pull-out drawers. I take the top drawer out and they have a nice, deep bottom drawer to jump down in and nest, and I get to open the drawer to collect eggs :B I've also used plastic trash bins on their side (turkey's favorites), retired totes with lids on and a hole cut in the side (chicken FAVORITE), or really any 'sneaky hidey hole' they can disappear into and lay an egg. Old feedbags make great flaps to cover nesting spots.
For perch/roost space, 6-8" is all they need or use. I like to offer a variety of perch widths and heights so they can pick their most comfortable spot. I like to use smooth, dry branches that taper and fork. The birds always pick their favorite spots and arrangements. This is nice too if you have young ones growing; they'll move around the perch to their comfort as they grow.
's headaches are predators. I've lots very few chickens to predators for the hundreds and hundreds I've raised. I attribute it to having trustworthy dogs freely running the same ground as them. Also having well-dispositioned heritage turkeys in the flock can save the birds' lives. I've had turkeys attack skunks and hawks. And dogs, when they have poults. My best turkey tom was my flock watch dog; he'd roost on the roof of the coop every night and if he gobbled in the night, I can running with the .22!
I'm dealing with a headache right now of egg eating. I switched grain suppliers and bought a few tons of specially mixed cracked grains, supposedly at 16-18% (supposed to be 16% but he accidentally added a disproportionate amount of peas, so the protein should be much higher). Problem is, the flock seemed to be really low on protein; poor yolk color and ravenous for eggs. I noticed they were picking all the wheat berries out of the feed and eating nothing else! The boogers! This is why I've always avoided feeding wheat; no protein value and it's an addicting easy source of carbs. So I started fermenting the grains again and they no longer can pick out just the wheat. Egg production is way up and the egg eating has stopped in all but 1 hen (who is not living with the flock until she stops). Woohoo!
Other headaches people run into are broody hens. Personally I love a good broody cause I love hatching eggs. But if you never intend to let a hen sit her own eggs, shoot for breeds that aren't broody prone. One of my favorites are Ameraucanas; cold hardy, chatty, friendly, beautiful beards, excellent layers, and bright blue eggs! Never had one go broody on me. Many of your larger-bodied hens are broody prone. Orpingtons are REKNOWNED for their broodiness, for example. My Marans are also very broody ladies.
Other other headaches are mean roosters. Personally, on my farm, a mean rooster is a dead rooster. I don't abide birds that think they can attack the hand that feeds them. Some people don't mind living with a mean roo though. Some people think it's fun. To each their own. I also think mean roos breed more mean roos, so my breeding boys are super docile and calm, which may attribute to having very few man cockerels around here.
Other other other headaches are illness and disease. Sometimes birds die; sometimes it's freak accidents, sometimes predation, sometimes it's unavoidable complications, and, albeit rarely, sometimes it's disease of some kind. I learned not to get 'too' attached to the birds when they can be frail and everything wants to eat them. It's always the ones I like the most that go e_e