It wouldn't be RPG-like, if there weren't any kind of classes / jobs. Yet I do not want to restrict anyones freedom so they merely act as a guide and give some bonuses.
Warrior
Commonly those talented in Material arts and boast in physical prowess choose to become a warrior. They often take on straight forward missions such as escorting, guarding and subduing enemies or beasts. This does not exclude those who excel in Ki arts. They also may chose to become a warrior.
Bonus
+50% DMG and CC effectiveness of Martial Arts
+50% more rewards (except unique) from Escort, Guard and Subdue Missions
Mage
Commonly those talented in Ki arts and prefer to use their knowledge, wisdom and spiritual power choose to become a mage. Missions that are linked to riddles, mysteries, rituals (such as sealing) and so on are most commonly taken on by mages. Of course those who prefer Martial Arts are not forbidden from becoming a mage.
Bonus
+50% DMG and CC effectiveness of Ki Arts
+50% more rewards (except unique) from Riddle, Mystery, Ritual Missions.
Watcher
Commonly those who chose to become a watcher, aren't to talented in any kind of offensive art, but will mae up for it with an agile body, good reflexes and intuition and a balanced mastery of martial arts and Ki arts alike.
Bonus
+50% effectiveness of non-offensive & non-defensive Martial Arts & Ki Arts
+50% more rewards (except unique) from Information gathering & trading, infiltration, duping / tricking and other similar missions.
Tamer
Commonly those interested and / or talented in Beast-related Arts chose to become a Tamer. They usually take on all kinds of missions related to beasts, such as locating, subduing, taming and breeding. They tend to be physically fit and excel in beast-related art such as beast-transfiguration, summoning & rituals (contracts).
Bonus
+50% success rate for soul binding and & +50% effectiveness of beast-related Arts (transfiguration, summoning, etc.)
+50% more rewards (except unique) for soulbounds and from beast-related missions.
Artisan
Commonly people interested in crafting and support other indirectly, as well interested in economy(money) would chose to be a Artisan. Ideally they posses high physical and mental endurance and posses a cast Ki pool and show finesse in controlling their Ki.
Bonus
+50% success rate for crafting anything magic/spiritual non-consumable (weapon, armor, accessory, device, etc.)
+50% money from trading / selling and +50% more material gain (except uniques or special event materials) from all quests (except main quests)
Alchemist
Mostly people interested in medicine and supporting but also those with interest in economy and money would chose to become an Alchemist. They craft all kinds of consumables such as food and medicine, but also other medicine and poisons. Like Artisan it requires great physical and mental endurance and a vast amount of Ki and Ki control.
Bonus
+50% success rate for crafting anything magic/spiritual consumable/medicinal (Pills, Pots, food, etc.)
+50% money from trading / selling and +50% more material gain (except uniques or special event materials) from all quests (except main quests)