Sadly, I think the marans is the daddy for all of them as my frizzles and silkie roos seem to be incapable of performing the needed motion. I have seen them try but mostly it's a pathetic effort at best. I suspect the peace in my coop with the many roosters I have is due to my big boy just laughing to himself at the girly roos fumbling around. sigh.
I do not know about the sex link trait on them. The only one that looks different is the little greyish one that came from the light green/white egg and the little dom egg. Even the green eggs that hatched look very similar to the cuckoomarans/black marans mix.
In my last 3 batches, I couldn't tell who was who until they feathered out. The cuckoo marans were barred black and white and the easter egger mixes went from lavendar to my brothers speckled mutts. He also got some phoenix crossed with the easter eggers as their tails are longer and their coloring is beautiful.
My only consolation is the grey baby I hatched a few months ago is still beautiful, one of my cuckoo/black marans mixes is incredibly sweet as she follows me around the coop just waiting to be held. My brother got the best mixes in the hatch I did for him last time which is why I'm hatching more for him now.

This time, without the phoenix, they just seem more boring. It'll be interesting to see the color of the phoenix/easter egg crosses.