I have been wanting to tell you this for a while, I just keep on forgetting, but I love your profile picture.1. Yup, they're very broody. Mine go broody a couple times a year.
2. They might lay a few times a week. The eggs aren't huge but they're decent sized for a bantam.
3. They make great moms! A lot of people use them as natural incubators because they're such good parents.
4. The majority of cockerels and cocks I've met have been quite nice.
5. They'll be fully grown by 20 weeks or so and probably begin laying 22-30 weeks.
If you want REAL Silkies, go to a breeder. Hatcheries churn out birds that somewhat resemble Silkies, but they do not have nearly the type you would expect from a proper Silkie. (Which basically means significantly less fluff and probably a very small crest, potentially no beard).

Six of one, half dozen of the other. If you want any chicken that's more true to the SOP go with a reputable breeder. The overstock will be easier to sell at a good price as well, I would assume. If that's not important and you just want good chickens go with a hatchery. Some hatcheries do advertise better stock in certain breeds they carry. Just my two cents.