Multiplayer/single player character

Ive been playing the Game with Friends for a couple of days but since we playing multiplayer, I havent touched the single player Mode yet.

I have 2 main questions:

Can I play with the same character or do I have to create a new one?

If i can play with the same one, do the talent tree/skill tree and the weapon/mining levels reset with the world? As in, if i farm a lot of exp with the sword in single player, does It carry to multiplayer (or viceversa)?