Babies suckle not just because they are hungry but because they feel scared or insecure about something. Suckling is a form of comfort for them.
Personally, I feel that if your baby does suckle for comfort once in a while, it's okay. But if your baby wants to suckle for comfort all the time, maybe you need to look at what could be the cause of this suckling - new environment, uncomfortable temp/clothing/etc, illness and so forth.
Having said that, some babies are naturally hungry all the time and would want to feed every hour. The only way to be sure is to feed them.
I have never intro-ed the pacifier to Eva mainly because I believe that I should be her source of comfort should she ever need affection or attention, and not the pacifier.