@ feather13: I am sorry you had bad experiences with aggressive chickens. We never, ever did. It might be the breed. I don't know breeds too well, but I think that we always had Leghorn when I was a child.
I know, however, that a cleaning lady of ours, who kept chickens and to whom I had given a bantam leghorn rooster (who had escaped from our nasty neighbor's conveyor killing machine into our yard) was pecked awfully bloody on a daily basis by this rooster. (She didn't mind, as she was so proud of this small rooster to protect "his" flock of 30 big chickens from her.)
Hope your li'l dinosaurs will not only stay docile but will come to love you. I am sure that the chickens we had while I was a child loved us. And if we keep feeding corn on the cob and grapes, our present chickens (4 different breeds, none leghorn) will probably love us, too. As Bine says: "Liebe geht durch den Magen." and not only with chickens.
You are right about (most) dogs being high maintenance, at least, when kept as dogs should be kept (that is, either being walked regularly and for long times or having a farm or ranch to roam). Unfortunately, our 2 dogs cannot be walked on a regular basis (because we have no time and also because I have health problems). And since they will not stay on our 18-acre property (or even close-by on BLM), no matter what we do (we spent 4 months, several hours a day to train them to stay in the vicinity, but not a chance), they are now confined to a 1,000 sqft dog yard. I consider this a "Hundeleben" (dogs' life), but it can't be helped.
Cats are usually low maintenance; that is, when you only have a few. We, however, have presently 27 indoor-outdoor cats (all fixed rescues), and most of them are old-timers (= 15+ years old), with about 6 of them ailing and requiring medication. So our cats are, meanwhile, also high maintenance. (Our high was 35 cats, and they were relatively little maintenance because, at the time, they were younger.)
Our chickens have, so far, been high maintenance because we needed to get their winter residence as well as their summer residence built, at high cost. (A friend remarked that they better lay golden eggs to have the cost come in.

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