Hi, A. --
We were definitely aided in soothing our otherwise unsoothable daughter with a pacifier. I'd been dead-set against it, for some reason, but after she was about a month old, we tried it, and it really helped her relax. She, too became very attached to it.
I think you're certainly on the right road in thinking about when the paci should make its departure, and I also think a staged approach is a good one. I'd say eliminating using it when he's not in bed is a good starting point.
When our daughter was about 2, we started talking about the "pacifier fairy" who would be ready to come take her paci to another little baby who needed it as soon as she was ready to let it go. We talked about it for several months and even told her where we'd hang it for the "fairy" to claim it. After a couple of nights where she gave it up but then reclaimed it, she decided she was ready to let it go for good.
I think it was important that she understood that the paci was for babies and she was getting to be a big girl and a good sleeper who didn't need to have the paci to be able to sleep. Then, it was her decision to part with it and let us know when she was ready. Within reason, I think it was a fair approach. We wouldn't have let her have it passed her second year, so we started the gradual transition to phasing it out just after her second birthday, to give her time.
She's never really mentioned it since, except maybe once in passing. She's slept fine and has plenty of other comfort items to make her feel safe and cozy at night.
I hope this helps!
H.