So... I know many ppl were upset about how Red Mage got gimped in FFXI from a melee-mage to a mage with little melee capabilities unless you sub Ninja, but that would leave you party-less. However, even that didn't live up to the old Red Mages past. It would be totally awesome if there was a melee-mage type class in FFXIV such as the Blue Mage or a tactical mage like the Scholar from FFXI. Maybe bring in certain classes/jobs from previous games that were job specific like the Green Mage, the pure defensive spellcaster class and some enfeebling spells that related to it's class. I suppose this is where bring in the job system comes in doesn't it?
Also, this may come as a bit late, but I rather did like the unique class names; Conjurer (Elementalist/Sage from FFT?), Thaumaturge (Warlock from WoW?), the Gladiator (Paladin minus spells) and Marauder (Warrior) >>> Pure defense class and pure offensive class respectively. However, the uniqueness also comes in when you cross-class. For example, Gladiator + Conjurer Cure and Defense spells = Paladin. Marauder + Thaumaturge "Absorb-" abilities aka Dark Knight from FFXI. Though I'm sure ppl may have figured it out by now, but for those who haven't, for cross-classing to work effectively, the answer is reaching at least rank 36.
In terms of customization, if this game were a truly customizable game, it would be similar to FFXII where each character can use the same weapon, but their path/strength/style of play depends on their unlocked ability chosen by the player. Mabinogi is also another good example of being somewhat semi customizable where player can use any "basic" ability with any weapon, however the only major abilities like high lvl spells can be used by a person with a wand.
There's also Pandora Saga that's semi-customizable, but the customization part comes from a class having the option/ability to become a different playing style. And example of this would be what happened in FFXI when Ninja was introduced. You started seeing two types of White Mages. One with mage gear and the other with STR+ gear carrying heavy duty clubs. Though technically this game already has that, it's just that it takes so long just to get to that point. Not that it didn't take twice as long as it did for the other games too. Of course, you don't want to get to the end too fast either otherwise the game would be over.