If you don't like beards on chickens, then you might as well choose a non-bearded rooster (unless a bearded one is much better in some other trait that matters to you.)
From those WTB cockerels, yes you will get lots of white chicks. They have the gene called Dominant White, that turns black...
There are several genes or combinations of genes that can make a chicken look white, so it can be a bit hard to predict. But if you choose a cockerel who shows little or no white, he will probably not produce chicks with large amounts of white either.
If you post photos of the specific...
Probably not.
Black (or blue) Copper Marans have no crests.
I've never read of a Whiting True Blue having a crest either.
If neither parent has a crest, then no chicks will have crests.
As long as the rooster does not have barring, yes you will get sexlinked chicks.
The chicks should look like black chicks, with yellow dots on the heads of the males but not the females. They should grow up to be mostly black, with white barring in the males but not the females. Both genders...
It would also depend on what kind of Marans you used.
A Cuckoo Marans rooster would produce barred offspring of both genders.
Cuckoo Marans hens with a not-barred Whiting True Blue rooster is another way to produce sexlinks.