Since there are players who don't want to be part of an FC or maybe even buy personal housing, they need an option to train etc their chocobos.

Why not actually make the chocobo stables that are around Eorzea actually functional?
Unaffiliated players could stable their chocobos at these stables and get to enjoy the content they otherwise can't participate in?

For a stabling fee they can train and feed their chocobos. Fee waived of course if they agree to shovel out the stables everyday.