One thing that I’d like to point out; the sorc/mage class, in a lot of games, is one of the more difficult roles to master. In Tera, it’s a bitch but once you master it, it’s devastating! My biggest problem in Tera is controlling myself so that I don’t steal agro from the tank (at upper levels, that’s suicide). It was a bitch to master but, boy, is it satisfying!!!
MMO’s have a lot of grinding. This allows us to master our skills. I think that you will be amazed at what we can master over time with a lot of repetition! I look forward to finding out!
I highly recommend that you grab a group of people for each role and have them “practice” your roles over time and see what they can learn. I, in my magnanimousity, volunteer for that testing, of course! 
