Post #8 is a Roo. No idea on the breed, but that is a boy.
Post #9- Blue Cochin You're right Roo-ish, but not a guarantee. I sorted a Blue Cochin hatch and put a chick just like that in my extra Roo pen. One day all the boys started fighting. Whoops, it was a girl and all the bachelor were competing for her. Likely boy, but I'd hold out for a while... It could still be a pullet with early comb development.
Post #3- Looks girlie to me. I think you might be wrong on this one.
I think #10 who you said was a rock is a Dominique. I think this b/c the barring is very regular and Plymouth rocks and cuckoo marans tend to have more "spotty" or "broken" bars - whereas Dominiques look more stripey. I am a beginner though, so just my two cents.