Will they maintain AP cost for native abilities?

[northernsky]

This makes me think that the action bar and the "list of use-able abilities" could be 2 different things.

Right now it's the same, i-e you can not use an ability that is not on your action bar. But if they make all innate abilities useable, plus a short list of cross-class abilities of your choice (same way that Blue mage would choose its spells), then from those 2 groups you could customize your own action bar.

That said, we would need a way to access all those different abilities that do not fit the action bar during a fight. Maybe an action-bar slot could be a drop-down menu for the remaining, use-able abilities that do not fit the bar.

You still have access to these abilities in fight but you keep the convenience of the action bar only for your top 30 abilities/spells. I think this would be mostly useful for mages for which spells quickly fill up the bar.

[Sorel]

But we have to think about how this will scale, too. A drop down menu with every ability a character has learned from all their classes could be too unwieldy to navigate effectively. It would only get worse as the level caps get raised and more abilities and classes are added to the game.