You need a vapor barrier or your floor will curl up and die.
As far as gluing it to concrete it may stick in some places but you would have a helluva time changing it in the future.There are some floors that float on a pad that do hold up to thaffic, they just cost more.
Buy the time you put in a subfloor for your woodfloor and raise a few doors and your baseboard if needed, you would have paid for it.
I always like to take the approach, will I pay for it upfront and get what I need ,or go on the inexpensive side and end up with MORE work.
Show me the money!!