at the start of the game you have a choice as to whether or not you want to use the standard or expert grid.

yes you do have to teach the basic abilities, however it doesn't have to be to the same person. for example you could make tidus your white mage and have yuna as your strong attackers if you wanted.

there are less nodes on the expert grid than there are on the standard grid and it does look a lot different. however it works on the smae principles.

i would recommend just using the standard grid as it has more nodes and so it is easier to max ur characters stats. it should be noted though that there are more locks on the standard grid thasn there are on the expert grid.