Ill give this a go but I am pretty new myself...

1. You need to setup ISBoxer to IWT - Under KeyMaps / Non-Combat there is a Interact With Target. I think by default its not configured to an actual key in game.

2. Druid is the only class that has all 3 roles and can stay ranged. But you can always just run to the instance and manually zone in and out.

3. If you have a higher level toon then boosting is pretty fast imho. Use the high level toon to group with 4 of the toons and just keep running through the instance. There is a "My Leveling Plan 1-90" in the WoW Forums here.

Just my two cents...