I dont play summoner, so ill leave it to someone with experience to answer that. Though i will say, as of this writing we're still guessing as to how things will play out. We've seen ability descriptions and some media members have played with an out of date build. But right now they are doing last minute tweaking and changing that no one will find out about until they actually get to play for real(and even then, theyll continue to make adjustments after the fact) this upcoming weekend.

As for Red Mage, leveling something up to 50(doesnt even need to be a caster - if you wanted you could be a tank from 1-49 then switch to red going forward) will meet the level requirement. Ive both heard and not heard about a potential quest requirement(finishing the 2.0 story), so we'll see what the final verdict is on that.

Black Mage, on the other hand, im qualified to talk about. So i enjoy BLM, as do many other players. The playstyle is essentially that of the cannon. You hit hard, but you have to be mostly standing still to be at your best. Some fights this is easy(there are fights where once i establish my initial position, i wont move a step), some fights test your ability to find/make breaks in your movement to continue getting off the big spells. And while yes, we're losing Physick, it wont be a huge deal. For a BLM, physick is useful from level 1 until about 30. From 30-50 its marginal, and after 50 the damage you can heal with it is rediculously small(yay my 600 point heal on someone with more then 20k hp). However, one of the new role skills youll be able to choose(at level 16 according to the media tour) is Drain. So if you want a heal for soloing, you still have it - only now it hurts the enemy too. Another thing to keep in mind is that you dont have the whole toolkit yet. Around level 20 youll get a chocobo to use as a mount, and around level 30 theres a quest to train your chocobo to fight alongside you. As you work with your chocobo, it will gain skill points you can use to teach it new skills - and yes, this includes healing abilities. The preliminary look says the BLM will remain similar in the expansion. A few buffs have been changed, but the playstyle is the same - hit hard with medium-long casting times. We look like we'll continue to do good damage in both single target and AoE situations.