Wyandottes are a little different. Maybe it's because they have rose combs instead of single combs. Whatever the reason, we see the laced Wyandotte females with larger, redder combs at an early age pretty often in here. The thing to go by with them is the evenness of the lacing, particularly on...
It's too early to say with certainty, but my guess is that they're both cockerels. Within a few weeks males will show the deeper colored shoulders and the long, thin, pointy saddle feathers, so 12 to 13 weeks is the best time to tell gender.
They look right for white Legbars, but there are no guarantees unless you trust the breeder. Too early to tell gender but so far no signs point to any of them being a cockerel.
As for breeds,
2 is probably a Sapphire Gem or some type of egger
3 is a Legbar cross type olive egger or Easter egger
5 is a blue laced red Wyandotte
7 is a typical Easter egger, the type that was around before all the new designer Easter eggers the hatcheries are now selling.
I think it is a cockerel, too. The pictures aren't too clear, but the size and color of the comb indicate a male at 12 weeks old. Females would generally have smaller and paler combs at that age.
Tough to say for sure. Both are bearded, and they probably got that trait from the OE father. OEs aren't typically white, so the mother of the white chick probably was. Maybe a Leghorn or white rock. The other isn't as easy to tell, but when it's older it might be easier to make an educated guess.
It's either a cockerel of another breed or a Sapphire Gem pullet that is developing early. Male SGs should have the white spot on the topside of the head and barring, but this has neither.
1 buff Orpington female
2 buff Orpington male
3 blue laced red Wyandotte male
4 maybe a splash Andalusian or some type of hybrid. Female.
5 black lace3d red Wyandotte male.
The gray one is an Easter egger, as you guessed.
The blue one could many breeds-- blue Australorp, blue Andalusian, blue Orpington, etc. It is a dark shade of blue, not black.
She could be a Sussex mix, but one of her parents has a pea comb, which is dominant over regular single combs genetically. To me she looks like some kind of Easter egger. So maybe she'll lay blue or green eggs.
1 Rhode Island red
2 Blue Andalusian, blue Australorp, blue Orpington, blue copper Marans
3 Partridge Plymouth rock
4 Welsumer
5 barred rock
6, 7 maybe Easter eggers
8 same as #2
9 cuckoo Marans or maybe olive egger
I edited, but it still might be off
12 weeks is when the males usually start showing male specific feathers. Those are the long, slim, pointed feathers males get in the hackle and especially the saddle area.
But in the meantime just keep an eye on the comb and wattles for increased size and redness. If things stay pretty much the...
As far as space goes, I think you'll be okay for another couple of weeks. But then you should move them to a bigger space.
As far as the heating plate goes, I would probably leave it the way it is for a while longer, until some of the smaller chicks get more feathering.