I am going to lay engineered wood over concrete and the section in the kitchen has vinyl glued to concrete. Can I lay over the vinyl and if so is there any special adhesive I need to use and prep work I need to d?

I have been reading on the message board and some have talked about moisture concerns. Should I be concerned about this with a slab foundation and if so what do I need to do?

Some manufacturers actually state in there instructions, it is OK to put sheet vinyl down as a moisture barrier and glue over that with their adhesive. Other manufacturers don't recommend it and require the vinyl be removed.

Yes, concrete is a major concrete for moisture vapor emissions(vapors cannot be seen or felt)

In the places where there is no vinyl, you spread the moisture barrier down let it dry and then the adhesive correct?