I like to have chocobo's of course as mount's but would like to see other feature's as well not just used as transportation but as an companion.
1. Add an area or settlement for chocobo's with like a grand chocobo as an leader. Where you can raise, train, custiomize your chocobo ie color, equipment etc to you're heart's content. Have fame, advancement rank for chocobo's with cutscene with your chocobo. More could be added in the future.
2. Be able to summon them not with an item that could take a valuable item space but an simple command text or whatever.
3. Have them were you can summon them in battle were after extensive training can transform your current weapon,armor depending on which you've train giving a hp/mp and stats boost to your weapon or gear.
4. Have another feature where they go gather item's or store gear item's from your adventures.

I'm pretty open to different view's on this just like to see something more to chocobo's then just as a mount used to get around places...