I played a Guardian to 40-ish in the betas and currently around 20-ish. I don't feel it's very involved. I push 2, 3 and occasionally 7 and 8 [heals] when low HP. It just doesn't really matter a whole lot.
The most involved part of the process is simply moving. Common to many games.
I would disagree on both games. But whatever floats your boat.Aion was a very simple game in comparison, as was SWTOR.