Yes, they are good brooders, but they are not the only broody breed. Cochins are as well and are hardier. Silkies do not tolerate cold weather well, but Cochins have a hart time in high heat. They go broody around one year of age usually, but some individual birds never will. It's a good reason to get a few.
In my experience, they are fine with their fluffy feathers covering their faces. There are also beardless varieties of silkie that have no crest or beard if this is something you're concerned about.
Finally, yes they get picked on more than other breeds. They are extremely docile and easily traumatized. They do much better in groups of two or more silkies because they can form their own sub-flock. You have to be prepared to remove bullies from your flock of you want to integrate silkies and be present and observing for the first week or so to make sure they are safely settling in.
I would have to completely disagree with the statement that Silkies do not tolerate cold well! They do just fine in cold weather (from much experience
