I've been lucky with my three and not had the bitting issue. The comment about teething is probably pretty much on the nail. I know with George when he was a kitten he would try and get my finger in his mouth to chew on rather than bite. It really did just remind me of a baby teething. He seemed to actually like it, especially towards the back of his mouth.
My friend's cat used to bite. Like you say it wasn't because he was viscious, just didn't know how hard he was hurting. When he did it with me I just just to say ouch quite firmly. The little minx would then immediatley lick my hand where he had been biting to say sorry
Again I agree with the advice about not tapping the nose as, if it does hurt him, he will assoicate the pain with your hands which a) will make him worse and b) will make him scared of you reaching down to stroke or pick up.
He's a mischievous little bundle of joy and still young and finding his boundaries with you, your OH and Bebe.