On the merging of casual into ranked, I'm opposed to it. It would just kill the mode (and the potentially coming dual queue as well).
Having been a big defender of the per job ranking option (I don't know who came up first with it):
1) It may be incredibly easier to carry with melee jobs and specific ones (DRG, GNB, etc) especially at lower ranks, doesn't mean it's a painful experience to rank up with team oriented ones. If you're good enough you'll climb. Anybody knows it takes more effort to climb with team focused jobs, until you reach a point where your skill with even more individualistic jobs averages over 50%, and then it becomes identical. I fail to see how this is a problem. We have many people way past gold that do main support or team focused jobs (ranged, buffers, etc). Maybe there is less of them even in high crystal, but that's a problem of meta there if anything, because some melee jobs like VPR don't fare much better.
2) I do understand it may be frustrating to have longer queues when a job is saturated in the games you play, but that's like queuing as a DPS in pve: you can choose to keep doing it (it pops eventually, it's not like you're getting 1/10th of the game pops anyway), or you can choose to try and rank up another job. I understand your argument there, but I don't think that's a problem at all.
3) That could be a problem for very high ratings (with the coming Ultima and Omega ranks). On the other hand, they're also no lifing this so...