On the Cinccino matter, it's in B-Rank mostly because it hits really fucking hard with Skill Link Tail Slap, making all of its three main moves at an obscene 125 Base Power, and 95 Attack is decent enough for it to be quite an offensive powerhouse, and it's pretty hard to take a hit from it. Bullet Seed and Rock Blast are both excellent, the former hitting Rhyperior and Swampert for some real good damage while Rock Blast shits on Chandelure like a boss. Cinccino is also quite fast, and without Steel-types or Cofagrigus/Dusclops, you're pretty much going down against Cincy. It's helpless against Steel-types and Cofagrigus, which makes a teammate like Houndoom or Chandelure ideal (or Magneton), and it also is frail, plus Tail Slap can miss at the most crucial time, as said before. However, Cinccino's ability to sweep while also serving as an anti-lead (which I forgot to mention), beating Froslass and to a lesser extent Scolipede, which is nice, make it a pretty solid B-Rank Pokemon imo. Like most B-Rank Pokemon, Cinccino is a great choice in the UU metagame, although it has some notable flaws that prevent it from being A or S-Rank.
You know, I'd be perfectly fine with Chandelure going to Low S-Rank. This thing has only one hard counter in all of UU: Snorlax. If you ask me, Chandelure is part of the reason everyone runs Snorlax on their team. As Magcargo 2 said, P2 and Houndoom see use because of Chandelure, and even they can lose. Chandelure just hits insanely hard and is very hard to switch into. It's slow I guess, and its SR weakness sucks, but it's powerful and is kinda versatile (Specs, Scarf, SubSplit), and could fit into Low S pretty well.
I'd support Heracross going up too since although the Scarf set is easily prepared for, the other sets can easily catch people off guard and are pretty awesome. SD Hera is one of my favorite things to use in UU right now, since he sets up, and sends slow teams crying for mercy, and is pretty hard to switch into. CB Heracross, I haven't used, but Magcargo 2's examples make the set look pretty appealing, and common Heracross counters are taken down pretty easily. I'd support it for S-Rank, albeit Low S.
Gligar definitely isn't B-Rank, keep in in C (and it's mid-low C imo). Gligar can't counter half a damn number of physical threats in UU; SD Hera sets up on it for days, Mienshao and Cobalion can run HP Ice (and the former can also just U-turn out anyways), and Scrafty and Machamp have Ice Punch. This severely hinders Gligar's ability to wall Fighting-types. Gligar is also big-time momentum killer, since as said, anything it can wall can just switch out, and suddenly Gligar can find itself facing something like Suicune, Kingdra, or Shaymin ready to just murder it. U-turn seems decent, but that doesn't help that Gligar is letting a free setup turn and such. (As I said, since Gligar is weak as hell, it's setup fodder to the absolute max)
I'd suggest Yanmega for A-Rank, since it is very capable of sweeping teams with just hazard support alone. Its access to Speed Boost makes it insanely difficult to outspeed, while it can fire Bug Buzz and Air Slash at everything which makes it pretty dangerous. Yanmega can really put you in an excellent win condition, like Sharpedo, thanks to this. Yanmega isn't just a Speed Boost sweeper either; it can also serve as an excellent wallbreaker thanks to Tinted Lens, and Specs Bug Buzz that nothing resists is pretty awesome and allows Yanmega to break down walls. I think Yanmega is pretty awesome in the UU metagame and I'd suggest it for A-Rank.