Old(ish) thread but I'll reply anyway for future readers.
I've lived in Celbridge for about 4 years now and there's no 'bad' area that I'm aware of. I wouldnt be a fan of the estate Dara Court, no trouble as far as I'm aware but I just dont like the look of the place.
I would advise you, depending on your commuting circumstances, to look at places on the 'dublin side' of the river. If you have to venture through the village every day it would be a pain. Plus on the dublin side of the village you are near both train and bus services for the most part. Downside is that houses on that end are fewer.