Well Time Mage wouldn't get Meteor but Black Mage would should they implement the spell. Time Mage could get the Demi line but would be a little broken online unless it had a beefy MP cost or an insane cool-down.
As for Summoner, think of a way for it to fit in this current battle system. I could see it as a summoned pet that had it's own AI akin to the elementals in XI but I could also see it as being much like the old titles like someone mentioned previously. However, I think it would work as though we personally learn the abilities. Take Aerial Armor (Garuda's in XI and just for example) which gives an AoE Blink effect. When we cast it, an animation of Garuda could be summoned quickly and bestow the party with blink. This would be a great way to make CON a required class since there's a summon for each element and summons typical learn the nukes. In any case, best to think simply right now using what we currently have for a battle system (that took nearly a year to change to).