Interesting take, but I am imagining something a bit different.
I think when the player starts off they'll be given an option of a fighter class (swords, axes, spears, etc) and a magic class (wands, staffs, magic casting, etc).
From there I think the player will have a multitude of weapons they can choose based on their class and using the weapon you gain proficiency in that weapon which in turn gives you skills. Maybe at some point in the story-line the player will be either be able to choose an 'advanced' class or will be assigned one based on their weapon prof.
For example, if you used a dagger for most of the game thus far you may end up a thief type class (given you started off a Fighter). If you focused on healing spells you may end up a white mage class (given you started off as a sorcerer.
Or maybe they can choose, who knows.
Of course, if FFXIV is going to retain the multi-job system they had in FFXI (i.e. more than one job per character) perhaps there won't be a need to "switch" jobs.
A sorcerer class can learn both white magic spells and black magic spells depending on the weapon they are using and on how often they use their skills. Obviously someone who wants to be a healer will use more healing spells, but at the same time they can also learn attack spells by using them more often.
In that sense they could be a hybrid class.
But maybe there will be "Ability points" that players gain and can choose where they want to put them? I haven't imagined it like that but it's possible.
I have the feeling that a player won't have to change weapons to use different skills, but rather different skills will be learned by using different weapons...at which point they can use them regardless of whether they have the weapon.
I also have a feeling that once a player chooses fighter or sorcerer (starting class?) that they won't be able to switch back and forth for that character. That's just a hunch...I don't know why I feel that way but I do.
Toasting makes me uncomfortable. But toast I love. Never start the day without a good piece of toast. In fact, let's toast to toast.