No need for sealant behind the retainers, on the outer of the bearing housing is a green o ring to stop oil going past it, and the cam seal stops any oil from the other part of it.
Did you put sealant under the cam carriers/caps, as oil can weep out the join between head and carrier.
I don't know if there is a "supposed" to trim on the cometic, just found I needed to for best fit, still leaves the tang under the half moon, just fits right after without being too long.
tabetha