Here are some ideas on how to bring rewards and lore to Eorzea though the Grand Companies. First would be a currency obtained though Grand Company related Content such as Missions, Quests, Grand Company related Instances, and maybe even somewhat a FFXI Conquest type system where you earn Currency based off a certain percentage of the total Exp you receive from an enemy but maybe that could be used in something different though I feel to a certain degree the more in different ways you can reward players for the most basic things like EXP parties, behest and Crafting the better, it just gives these things a feel of more sense of accomplishment when doing them. Anyways obtaining and using this Currency to buy Equipment and Items that are inspired by the design (in looks) and statistical properties of the Grand Companies (unique to each single Grand Company) is very important to help the Grand Companies add Lore and style to Eorzea, the Equipment that come from FFXI's Conquest and Campaign is an good example but needs to be more diverse in the looks department to set each single Grand Company apart even further such as Artifact Equipment did for each Job in FFXI. A way to obtain these currencies could be as simple as FFXI's solution which was to get a Status Effect i.e. Signet, Sanction or Sigil, I was thinking if that was the route to take maybe it could be call "Allegiance" (Name Tentative haha) obtained by an Grand Company NPCs or in the cases of missions and quests in some instances it is automatically put on you. Well that is some of my ideas i'll ponder on more later and maybe post them.