A piercer.
A psychologist is the proper name for someone who studies the mind.
The proper name for someone who speaks four languages is a quadrilingual.
combustion
If you mean the species of tree, it is not a proper noun. However, if you were to name someone or something "Birch" - it is a proper noun.
Chandler
It is a proper noun because it is the name if someone
Because someone didn't know the proper terminology and made up a name. Technically, it is simply a philtrum and a labret. Most of these "___ bites" names seem to simply be made up either by people who want a name to describe a specific pairing of piercings or by people who just want to look cool and don't think "paired labrets on the right side" works as well. (Yes, all lower lip piercings are technically "labrets" and all upper lip piercings are technically "philtrums.")
It is a proper noun, as it is the name of someone.
christian
ultracrepidarian
therapist
No, it is not possible for someone to cash a check that is not in their name without proper authorization or endorsement from the payee.