The same as Devile on the 3 points.

- You can't really mix melee and ranged class, however some ranged classes have melee templates now (DH with a dagger, WD with Firebats, etc.)

- Unless you are playing 4x the same class, don't teleport. Multiboxing has its advantages, but it's one of its flaws. Also you need to know (but you already do, since you are multiboxing WoW) that you won't do better than 4 real players teaming. Well... it depends on the players tho

- I haven't tried a Barb as support, but I generally play 3x same class and one support. The Maths are here... 4x1M DPS = 4M DPS but 3x1M DPS and 50% damage buff from last character equals 4.5M DPS... Plus other advantages, like ressource regeneration, protection, etc.

I haven't decided yet which combo I'll play this era. DHs have a very high DPS but they are still weak compared to other classes. At the moment I'm gathering new legendaries and farming materials with 4xWD (for rifts) and 4xDH (for bounties and rifts).