I love the whole materia idea, although I do think that possibly scaling down the materia to just 3 tiers instead of V is a system that could work better when it comes to U/U gear and rare gear drops from NM or dungeons, this way it still gives gear the ability to be almost on par with U/U and doesn’t take away the power of U/U gear. I also think some materia orbs could be rewards from chest found during guild leves, rewards from side quest or even rewards from behest, the orbs would be scaled according to level/rank of the quest or mission or leve.
Thoughts…