Baby...Pacifier  

I have heard, but only heard, no real proof. That babies that suck pacifiers when they are younger are less likely to die of SIDS because it gets them breath and moving their mouth or something along those lines. I think its okay to give it to babies, but once they get toodler age out they go (or when they start getting teeth). I don't think they need it after that.

Nah it's not likely - with a bottle they take in air coz they breath between swallowing - using their mouth as they have to let the air out of the bottle as well, with breast feeding they end up with very little air in there.
With a dummy they'd need to actually swallow the air in order for it to cause a belly ache & that doesn't happen coz they can breathe through their nose & still suck on the dummy. You can suck in as much air as you like but it wont cause problems unless you swallow the air & it gets trapped! Try it :)
My daughter hasn't had a belly ache from it yet!
My daughter sleeps easier with her dummy, otherwise she sucks on her fingers :)

Pacifiers aid in making the speech muscles stronger. Most babies have a need for sucking so a pacifier is good when they need it. I don't think that they suck in to much air with a pacifier. If your baby is on formula that may be upseting their stomach. Try Gripe Water for upset stomachs.

Pacifiers are suppose to be used for that purpose..to "pacify", but unfortunately some parents use it continuously and the child gets attatched to it and they feel some guilt about taking it away. I'm so against the pacifier after age one. I usually only use it while I'm driving or if in the shower while my significant other or older child sits with them, due to the fact that I breastfeed.
But I can see your point about sucking in air, that could very much be a possibility.