Blue Laced Red can really be black laced, blue laced, or splash laced.
A Black Laced Red chick might look a lot like a Dark Cornish Chick.
When they get their mature feathers, you should be able to sort them out (single laced vs. double laced), but the pattern may not be clear in the first feathers to know which is which.
It's quite common to have single comb birds show up in rose comb breeds.
You cannot tell by looking if a chicken is pure for rose comb, or if it has one copy of the rose comb gene and one copy of the not-rose gene (single comb.)
Crossing single comb to rose comb, either half the chicks should have rose combs, or all of them should have rose combs. It depends whether the bird with a rose comb has one or two genes for rose comb. Of course, all those chicks would carry the gene for not-rose comb, so when they have offspring of their own, you will see single combs show up again.