1. I say Plymouth because of the barring, unless they had other breeds in the Barred variety.
2. Has a rose comb so I believe part Wyandotte, probably part Cochin because of the feathered legs but this makes me think they have a barred Cochin cause this little ones barred

3+ some have rose combs like a Wyandotte, other are hard to see, I see no feathered leg so likely no Cochin in here, none of these chicks have beards so at the very least the parent birds have either no beard (like Cochin/Wyandotte or bad EE/OE) or the OE/EE parents only had one gene for beard and you got unlucky :/did you hatch them? Were any eggs blue/green/olive? I don't see any of the fun EE/OE colors or leakage although depending on which one the rooster was, black can be a pretty strong gene sometimes
I think those ones are probably cockerels due to comb size and redness :'(