Objective Analysis of Ranked Queue and Champion Select
The Champion Select I have the least number of problems with this. My biggest complaint is that, while it does delegate the role of banning to three players instead of one, it chooses the three least logical players as possible. The first, second and third picks are most likely to get counterpicked, but do not get to assign any bans.
I feel as though it should also warn you if you're about to ban a champion an ally has hovered as their preferred pick, but this is largely trivial in comparison.
The Queue: Regarding Role Choice Prohibiting players with the same primary and secondary roles from queueing together is ridiculous in a competitive format. For normals, it is perfectly reasonable to require two roles to be chosen, to hasten the process of finding a match. The point in normal matches, above all else, is an enjoyable experience. For the same reason, not allowing two people queued together to choose the same roles is logical, because it again helps the matchmaker establish a match more quickly, and players may become exposed to a role they're inexperienced with; this is good practice.
Conversely, in Ranked, the primary objective ought to be to cultivate a competitive environment and to maintain the competitive integrity. Therefore, it is illogical for the system to jeopardize their chances of winning by forcing one of the two players to play their third best role; a role they may not be experienced at playing.
The second objection I have to role choice is that if you main role X and your secondary role happens to be Support, you'll overwhelmingly receive support as your role. The amount the system favors your primary role over your secondary role is seemingly negligible.
The Queue: Regarding Party Members The biggest complaint with this is not the capacity for boosting that it provides or anything of the like. Rather, it is that a solo queue player can be matched with a 4 man premade and be forced to play against another 4 man premade. In a competitive format, this should not exist. The system should not be affecting your chances of winning this dramatically.