4 sq feet per LF bird minimum... I don't think the big guys would easily get into those hanging planters as most have a pretty thin edge to jump on
Birds are going to get things dirty so think of how you can clean easily.
Maybe hinging the roof or hinging one whole side to open?
having a tray of sand under the roost that can be sifted out once in awhile, or a slick board that you can scrap?
adding a pair of nesting boxes on the outside with a roof that lifts up so you can collect eggs and clean the boxes since they do poop in them. ( many coop designs are like this).
water outside, like the water nipple idea,or a bucket with a clip that can be cleaned often.
Ventilation is good, my coops are 6' high 3 solid sides and chain link panel front runs, completely open....I have never heated, have a light bulb in the winter, so far lowest temp has been 8 degrees, keeping floor/coop dry(using shavings) and protected from wind.
I haven't worried about numbers in the small coops because they have access to free range many days.
Feeders that they cannot beak toss the feed around....messy
i also have a small bucket (Danish fruit jam) that has the oyster shell/grit.
I don't know if you have rodents, racoons, etc. but i don't place youngster out til warmer weather and only with small mesh (1"x1" min.) for their safety. I have had a racoon try to pull a turkey thru chain link.
So these are just some thoughts?????