All this info brings up many more questions.
First, is the 4 pieces of gear from my level 45 job quest plus the gear from my level 50 job quest enough to complete the HM fights for my Relic Weapon?

Second, what GC rank do you need to be in order to buy i55 gear from the GC?

I'm sure I will think of more and I apologize that this turned into a gear progression thread as I know that information is VERY easily accessible on the forums.