Is It Possible to Cancel the Quest "Call of the Sea"?

[MsQi]

So just continue to do the quests below the MSQ in order to progress as a Conjurer? And thank you for your help.

You can do MSQ quests on whatever combat class you want as long as it is high enough level. That class will gain the experience.

EDIT: sorry, yes the one below the MSQ is the class or job quest. It will advance the class or job you currently are.