I think the OP largely nailed what I would want to see, get the International Version of the game, fix the audio and spruce it up to HD quality graphics. I would love to see Matsuno get hired on to retool the game like he did for Tactics Ogre remake.

The only new feature I would like to see if a retooled Bazaar that works like TA2's version so I don't need to look up a guide. Retool enemy drops so I don't have to dedicate 30+ hours of grinding to make the ultimate weapons, and a FFTactics style datalog that keeps tracks of the characters and story for me so when I do decide to just fap about Ivalice, I have something to get me back up to speed on the story.