If you want ease than keyclone is for you when it comes to sending keystrokes and setting up windows.

Mix classes are much more difficult to manage. If they are similar than its not such a big deal.. or as much of one. So a warlock and mage would be easier to manage than say a Rogue and a Priest.

i think having melee toons as your first MBox experiance will be tough but surely anything is doable. The hard part about melee is getting everyone to face the right direction during a shifting battle. When you first engage or run up on a mob you have to time when you stop just right and due to latency the clones might not stop where you want or need them to.