Initial Reservation:
Don't take the title the wrong way. I'm not looking for hard coded classes which make you choose one path (as of right now it'd be swordsman, gunslinger, and bomber) but rather a system where you won't be able to just change your character type to anything at all assuming that you obtain the equips for it.
Current "Problem":
People now can switch "class" simply by changing their equips. If a well equipped player decides to change from swordsman into bomber he or she can simply gather materials and start forging bomber clothes and weapons and suddenly he's a bomber. People can also factor their character to become a jack-of-all-trades type of knight where they use guns, bombs, and swords with generally the same level of proficiency. This is good and bad. Good because players are free to choose what they want to do and free to change their mind or pick a new path. Bad because the "classes" are not well defined and there is no clear advantages and disadvantages a person must decide on since they are able to switch to a different path at will.
Why would we want to address this "problem"?:
Weakly defined classes suffer from feeling week and mundane. If every person has the ability to be every type of specialist then there's really no reason to care about what you decide to do. Since each class is defined basically by the weapon the person uses and what kind of armor they have on, classes don't really get any unique powers or abilities. Each person feels like they can be anything and everything at the same time (they can't but they can change roles easily) and that's why it feels like a solo "Zelda" adventure where one adventurer covers every need.
A proposed solution to the "problem":
Don't make clearly defined, constrictive classes. This will make the game into another MapleStory/WoW. Instead give people incentive to specialize and stay specialized in one area or another. Make armor and weapon sets that give bonuses to specific weapons (e.g. the bomber outfit, when completed, will give additional bonuses on top of what the equips do naturally). Make people with a set unable to carry weapons that are not their specialty if it's above 3 stars (sorta like can't handle explosives b/c they're not an expert ^^). Make more specialized weapon/armor sets which give people within a specialty options. This way people will still have the ability to change specialty, but they'll be more inclined to keep with one or two instead of going jack-of-all-trades style. We'd see less people running around with a sword/gun combo and more people using 2 different swords and 2 different guns. People would therefore be more reliant on their party members while exploring clockworks, thus increasing the social atmosphere of the game. Maybe even include portals in clockworks which only allow parties with a certain number of gun/bomb/sword specialists to pass through. Players would become more diversified and less unified under a single "class" and I believe the game would have a better feel overall.
Unless you're playing the game willy nilly (read: idiotic) or trying to go solo, it's best to specialize in a weapon type.
Of course, it's easier to set up well-rounded groups with a clan than with public groups, but that's the nature of any game.