I'm having some friends over tonight for local co-op. I'm a few hours into the game already so can someone explain to me how multiplayer in this works?
1. How does scaling work? If I'm a few hours in and level 15 and my friends make characters to play with me, will they be useless in helping me fight monsters or will the game power them accordingly?
2. One of my friends already has a Battle.net account and is planning on picking up the game this weekend, if he signs in with his account on my PS4 when using one of my controllers, can he export his character that he makes today to use once he buys the game?
3. How does co-op work in general? Like lets say I'm playing with 4 friends and we're all at different points in the story - if they join my game and do quests with me, are those quests completed in their game as well or do they need to re-do it?