Seems like the right answer is that it depends on your child. You should know how much comfort they derive from it or need from it, and what ways of changing their behavior work best.
Make it a big deal. Gather all the pacifiers and have a big kid ceremony. Put them all somewhere where your child won't see them again. After that, everytime he asks about them, remind him he is a big kid now. It sometimes help to replace the pacifier with a new stuffed toys that can be used for comfort.
No. The child has a sense of security with the pacifier. I would recommend that the child not use the pacifier in a public places. Point out other children slighly older than the child when you make trips to the store showing your child that "big kids" don't use pacifiers. The child will eventually not use it anymore.
As you know your child is a bit too old for the pacifier. Despite it sounding mean, you are going to have to THROW AWAY THE PACIFIERS IN YOUR HOME. Do not hide them. Tell your child he is too big for it and offer a reward for good behavior.
I think that a gradual weaning is a better method than getting rid of the pacifier cold turkey. Some folks recommend that every day you cut a small amount off the tip of the pacifier and continue to do this every day until the pacifier is gone.