Trotters. Cool. What colors? Any pics?
Most folks recommend keeping a minimum of 10 hens per rooster so his "attentions" can be shared among all the girls. This will prevent him from wearing out one or two poor girls who would be the object of his constant attentions. Of course, not all roosters are created equal, and many of them are gentlemen who treat the hens well and do fine in breeding trios. Our little Serama roo has been very interested in his little pullet companion for many many weeks now, and so far he respects her refusals. You will have a choice of CL roos to see who treats the girls the best and shows no aggression to people.
Will a black x splash give you the possibility of blue offspring? I forget how the genetics work. Either of those roosters over a brown egg laying pullet will give you mostly green egg laying EEs. If you get a dark brown egg layer, you could get some olive egger offspring. (I'm not sure if either parent can have the blue egg gene, but I think so.)
Mixing your 2 week olds with older birds can cause problems, but you can try it with supervision. At night, there's no problem because chickens have terrible vision in the dark (no rods in the retina, only cones) so once they roost for the night, there is no hanky-panky. But the danger is in the morning if an older bird decides to assert dominance and draws blood, the others will join in (like sharks) and you will have a dead chick. Most people say to wait until they birds are close in size and introduce them slowly. How old are the older ones?
