I'm pretty certain that #1 isn't a d'anvers as they should have a rose comb, beard and muffs. Perhaps he is a black tailed buff Japanese? Does look rather roosterish to me.
#2 I wouldn't like to guess gender on
#3 looks girly (but 5 weeks is a little early to be sure)
The barred birds I have no...
The black chick I was referring to is in the photo above, has no white head spot, and is most definitely not a barred rock. Rhode island reds do not have white under feathers, those are red sex links.
Were these eggs that you hatched yourself? If so, were they sold as pure breeds eggs?
If they are purebreds my guesses would be barred rock, welsummer, and gold laced Wyandotte :)
Your grey chick looks to be part marans, which is a breed commonly used for making OE's. I would say that your brown chick is the Swedish flower hen :)