I understand that Yoshida and the Dev team are planning on making the first step to having chocobos as rentals. While having a ride that will kick you off at random times may give some reminiscence to past FFXI players, and while it would be a good additional gil sink that wont see much use because people will still be teleporting most of the time, I really think they should just skip the rental stage and move on to the owning stage. There aren't any MMO's i know of besides XI, and soon to be XIV, that you rent a mount instead of flat out owning them from the start. If they start from rental stage, it will only feel like they are XI'ing the game even more, and that they cannot move on from what XI was.

The quest for owning a chocobo should be made so that it requires pure dedication. A good way to do that, is that during the quest, you are not allowed to teleport or be teleported or return at all while doing the quest. It should also require you to travel to distant places. Perhaps even after the quest, a gil sink for it would be buying the reigns or what not for the chocobo. It also shouldn't require fighting anything, unless they have different versions for Battle and crafter/gatherers.

Chocobo's should start out being ownable and ridable at R/L25/30. These chocobos would just be the normal yellow ones, and not the fastest. At Rank/level 50, or in future expansions, It should be possible to acquire different colored, faster, and flying chocobo's. If there are absolutely no plans on adding swimming, certain non-flying chocobos can be used to cross water bodies or mountainous regions to get to other areas if they cant fly, like in other FF games (FF7 really). One way to do this, is to have Chocobo training for the one you own. By training your chocobo through training quests, your chocobo can learn do different things, and eventually fly. Another way is through equipment. Such that will help your chocobo float on water, or foot attachments for climbing steep hills and mountains, things that will be made by crafters as well. Both would be more un-like other FF games, but still FF.