Tales of the World: Radiant Mythology 3 Post-Game Discussion

Hello all,

I picked up Radiant Mythology 3 again and found I was post-game without the Sorcerer's Ring upgrade(s) nor all classes mastered with their signature armor set. As the past discussions about Radiant Mythology 3 have all been lost, could someone please remind me about all the optional post-game objectives? What level was it that the armor sets become available? Was it somewhere in Velatropa that you upgrade the Sorcerer's Ring? Including any information about optional bosses would also be appreciated.