It's hard enough getting your configuration ready for ONE team and ONE setup after the ease of levelling through RAF. IMO you are setting yourself an unreasonably high bar and dooming yourself to failure by trying to implement multiple DPS rotations with multiple synergies between different tanks and healers. I'm sure some people can do it, but I couldn't and it doesn't sound like you're ready for that either.

My two pennies worth - pick one team: the pally, the priest and the shamans and level them all the way to 80, come back and get the rest. Forget trying to be able to slot in whatever you want whenever you want. You can do that when you have experience.

God knows it took me long enough to get my single team ready for instancing. Given that you haven't levelled these toons bit by bit, new ability by new ability through earlier instances means you now have to learn the classes. Attempting to learn an additional half a dozen classes and, well, you end up understandably feeling like this.

Just pick the team you have the most knowledge with and/or are the most multiboxer friendly and learn with them. Read the forums, print out abilities and do some scribbling during lunchtime. That will maximise the time you can spend in-game.

The curve is steep at first but levels out surprisingly quickly - to the point where you'll soon be writing macros outside of the game, confident that they will work in game. Good luck and don't be disheartened - but don't make things hard for yourself.