I've always wanted SE to consider splitting Rogue into Thief and Ninja like they did with Summoner and Scholar. They could do something like Rikku from FFX and use the mix system to create different attacks in a similar way that Mudras work on Ninja. Ideally, they could have less personal dps than Ninja, but make up for it with strong RDPS buffing/debuffing effects via mix effects. Alchemist has been a decently requested job and this could be a way to work it into the game to be different from the crafter of the same name. Thief is about the only job that comes to mind that could share gear with Ninja and it actually make sense.