Hoping for a good answer.

1) No matter how balanced an MMO is, a few classes always stick out as being better than others or at the very least more often needed in a party. To that end, which classes are the most sought-after in mid/endgame?

2) Relating to that question, what is the most efficient way to level your classes (and I don't mean which mobs to grind or quests to do)? When I played for a few days in 1.0 I was advised to level... I think it was Thaum at the time but now it's Conj... up to the point where you get Heal so that you can use it to supplement potions while leveling other classes. Now, I've already done so, so I have that part finished. However, as far as the other classes go, is it better to level them all together, or to min/max like a D&D stat sheet? Yes, I min/max my dexterity and cunning on a rogue, stop looking at me funny ;P
(The forum is telling me the post is too long, so let me see if I can split it into two replies)