Dude you're no where near the end, you're about half way I'd say. Also although it's worth Mastering most of the classes, the one's I'd recommend are Summoner for !Call, Ninja for Dual-Wielding, Ranger for !X-Fight, and the three other mage-types for at least one character each i.e. White Mage, Black Mage and Time Mage. Blue Mage doesn't count, and Red Mage is only advisable if you really want to be able to cast spells twice in a row.