Try to let him until a year and then gradually take it away when they fall asleep, baby happy and Mommy happy too!
its ok to let them suck. usually once they are in deep sleep, they will spit it out. no need to force them:)
I feel that is OK to suck pacificer to sleep when they are in deep sleep they will push out by themselves :)
i find is ok. they will quit it by themself when they are older
Pacifiers helps to soothe baby. However it's hard to wean off