I think I got it now. Thanks!
Yeah, so since Monk has 2 subclasses (im still using this term) - marauder and lancer - it would make sense to figure out which skills i want and to level accordingly.
That sounds about right. You don't have to level Marauder at all to play MNK. But if there are any Marauder abilities that you want to cross class, it would be to your benefit to level Marauder so that you have access to those abilities. Similarly, level 15 is the bare minimum that you need to level Lancer, but you may want to level it higher if there are specific Lancer abilities that you want to cross class.
Yeah - specific example is Invigorate & Blood for Blood (both from LNC). Invigorate is a 22 LNC ability to restore a chunk of TP, Blood for Blood is a 34 LNC ability that boosts damage dealt & damage received. Your LNC must be 15 to unlock the quest that grants the Monk job crystal, but you'll eventually want to take LNC past 15, to get these 2 awesome abilities, that you can
use on your Monk. So: Base Class
: Pugilist Job
: Monk. Requires 30 PGL & 15 LNC to unlock quest, that grants a Monk job crystal. Equip this crystal while a PGL to change into MNK.
These are linked in level - 30 PGL = 30MNK, 36 PGL = 36 MNK etc. "Subclasses"
: Marauder & Lancer (Yes, not an "official" term, just one that has been adapted from XI) Cross-Class (PGL)
: Any ability from any class that has PGL in the required class/job list, at the bottom of the ability tooltip. You get 10 slots for these @ 50. Cross-Class (MNK)
: Same as above in definition, but the only classes that will have MNK in the required class/job list are LNC & MRD. You get 5 slots for these @ 50, along with 5 MNK-specific abilities.