Why does he do these things?

I have a couple of questions about our cat we call "Key-Key." 1st: Why does he continuously like my husbands face? My husband is getting a little aggrevated and has had to let his facial hair grow to stop it. The only time Key-Key likes his face (continuously) is when his face feels like sand paper. He has stopped that by letting facial hair grow but my husband doesn't like facial hair and wants to shave. Next Key-Key sucks on our ear especially mine? Why? Also Key (short for Key-Key) almost gets in a trans like state or gets really into what he is doing when he is "Kneading" and "sucking ears" that he not always but sometimes will do these two things, rub, and then take a little bite, why? He isn't aggressive he just does this bite thing sometimes! Finally, he wants to eat finger nails almost as if he doesnt want them there?

I'm sorry I'm smiling to myself here. Are you sure you're not describing my cat?
Sleeves licks his Daddy's chin every night and sometimes he can become quite agressive while doing it, like digging his claws in or giving him a little bite, I think it's to say keep still. He does it as a sign of affection, infact thats what the ear sucking is too. I know it can get annoying but they are just showing you they love you. I think the sucking thing might have something to do with being taken away from the mother too early but I'm sure someone on here will correct me if I'm wrong.
When Sleeves kneads the bed covers he is on what we like to call 'Planet Sleeves' he cannot be spoken to and that is the only thing in his life at the time. Its just they way they are.
We are not at the stage where sometimes Mark hides under the bedcovers when he see's Sleeves coming
Key Key obviously loves you you are very lucky