I will try to help but I have only experience with Silver Duckwing OEGB. Cochin will have straight combs, d Uccles should have muffs/beards along with feathered legs, d Anver should have muffs/beard but with clean legs, Dutch should have white earlobes (I have never owned white earlobes but think it shows more as they age) That is the main difference I see with Dutch and OE.
1-black or motted cochins
2-Light Brahma, Blue Cochin
3- could be Siverduckwing but there are other colors that look almost identical as chicks, probably OEGB
4- Probably OEGB
5-Looks modern by the station---if so could be-Brown Red, Black, Birchen, or even Blue because some will come black
6- Possible d Anver but hard to see if it has muffs, but if it does I would think Quail Belgian, if not possible Brown Red something
7- Looks like Blue or Splash something maybe OEGB
8-When you said "belgain quial is in the back, and in the front maybe a black OEGB" it could be or same as #5 but OEGB come in the same colors too, possible
Japanese
9- One on left looks like a Lavender (Self Blue) but it could be just white hard to tell or could just be blue. Possible OEGB, maybe even Wheaten
10-Possible OEGB
11-Possible OEGB, possible blue or splash
Sorry if I'm just making it worse, but after they feather out some and you post more pics it might be a little easyer and narrow it down. I did not see any that screamed silkie though. So that might cross one off the list. Have you tried to compaire to Ideal's selections, They have so many.
A-Brassy Back OEGB, or Crele OEGB, Maybe even Mahogany. It looks like it is going to be dark.
B-Leaning toward some kind of Blue or Red Blue (think that would be laced)
C-Maybe Buff Orpington or New Hampshire if yellow legged.
Keep an eye on the leg color too for the next few days. That will help id too.
EEs are still possible But none really scream that either but they do come in all kinds of colors.
Well of course they start after hatching, but it depends on the type or breed. OEGB should be complete around 6months but could take longer and a molt to see the true color. Cornish would be the fastest and only in a few weeks. Standard poultry take 3-5 months with good conditions (no feathers being pecked out). 1-2 months you should have a good idea what they are going to look like but then again you do have late bloomers. For crosses they can be different and be one color one year and molt out to something completely different coloring. As for B it could have just come larger because they don't always stay in the weight range, but if it is bigger I would lean more to Blue Cornish Bantam that Ideal has.
In about 2-3 weeks if you can post some pics you might can get it narrowed down a lot. They should have good enough feathers and leg color to see what breed they are, but might not know the exact color until they are older. Ideal has a large selection on color in their breeds.
At 5-6 months my Silver Duckwings looked almost like what they look like now as adults.