#1 no idea on breed, there are a few I can think of it looks like though XD I'm no good on the brown and tan chickens they all look alike to me unless I've owned them. but it does look like a roo...
Pic I think #4 is a light brahma pullet, the big chicky in the back.
the fuzzies are silkies in #3 and #4
and no clue as to sex silkies are hard buggers to sex until they get some good size on them and their combs and waddles develop if its a roo and even then sometimes you can't be sure till it crows or lays an egg in silkies.
pic #3 the white and black speckled one I have no clue it could be either way, it looks to have a single comb and clean legs, and again I'm not too great on breeds of birds I've never owned, but it looks alot like the light brahma mixes my neighbor has, except that comb. But that one makes me think roo, but the comb isn't very colored out...
How old are all these guys? I may be able to give others a better idea on development?
the little grey one in the back of pic #3 looks like a pullet. I have one that i got that was some sort of banny easter egger mix that looks just like that one.