Help me with Housing questions!

[Mhaeric]

Hello, I am levelling a new job, and I am considering a Job Boost skip.
Will that let me join a Grand Company to unlock housing without completing the Main Story Quests? If no, at what main story quest level?

A Job Boost skip will not let you join a GC on its own, no. Joining a GC happens at level 20 once you complete the "A Hero in the Making" main story quest. In addition, once you have joined the GC you will need to be at Second Lieutenant in your GC (the highest rank) in addition to being level 50 on your character in order to purchase a house. The only requirement a Job Boost skip will meet is the level 50 requirement. A story skip potion would let you meet the MSQ requirement and automatically enroll you in your GC in your starting city's GC, but not meet the GC rank requirement for housing which has no way to skip.