Why in the world would they not let us turn in Moogle Tomes???

[Catwho]

All the items in the moogle store are obtainable through other means

The Great Serpent of Ringa was exclusive to the event, so it should have been the first thing anyone worked toward.

But you are correct about all the other items. The emotes came from Eureka, the head mount came from PotD, etc.