Looks like you\'ve got some cuties & were blessed enough to get true Ameraucanas the first time, rather than Easter Eggers as many of us unknowingly did.
I\'ve had eggs from the same breeder vary quite a bit based on shipping & my incubator\'s conditions. That said, some breeders do test the fertility of their pairs each year before shipping any eggs while some may not, and some breeders are more knowledgeable and careful about hatching eggs than others.
Your chick in 2nd photo from the bottom definitely looks like a Blue. I\'m guessing the striped ones are Silver? Looks like there are 2 or more Blacks in 2nd photo from top, also.
As far as leg color, we\'ve had pink/orange legs on Blue & Wheaten chicks and they developed into slate. I\'m guessing your chicks\' will, too.
A number of our Blacks & Blues showed very little sign of muffs as chicks, but developed them as they got older. (One had very scrawny hackles, too, which later filled out rather magnificently).
Hold out hope! I\'m betting you have a lot of nice chicks there. It\'s obvious from pics (pebbles in waterer, good footing material, thermometer on brooder floor, cleanliness, etc.) that you\'re giving them great care, too.
Best wishes, Laura