Alright, so before I begin this post, I want to ask that we stay on point here. Right now, the thread is really erratic with all kinds of people pushing for their favorite Pokemon to be bumped up. S- and A-rank Pokemon are always going to be given priority in discussion, so if there are three or four nominations pertaining to those ranks, I don't really care if you want an E-rank Pokemon to be moved up because it's not going to happen right away.
On Snover: it's staying A-rank, and there's really no reason to discuss it. Almost all of the top Pokemon in the tier are weak to Ice, and Snover is one of the only viable Ice-type Pokemon in the tier. It can also give sun an insanely hard time, particularly if it can keep up Stealth Rock to prevent Vulpix from switching in a lot. With Gligar being the most common Defog user on sun teams and Vulpix typically being the only Ice resist that sun teams carry, it's not hard to keep the opponent from using Defog and taking out most of their team with Blizzard. I also don't get how you can call it weak when it has solid Special Attack and a 110 Base Power STAB with no drawbacks outside of sun lowering its accuracy. No, it's not switching in on a bunch of hits, but that's an utterly irrelevant argument because that's not why Snover is used. Carvanha can't take hits either.
Goomy was put into C-rank because of how easily it takes on opposing sun teams. That's pretty much its niche, and while that niche isn't going to be super valuable in every match, it does make Goomy viable right now. After Tangela gets the boot, it'll probably be worthy of D-rank, but right now, I see no issues with having the number one answer for Tangela and sun in general in C-rank.
Timburr is fine in A-rank. I prefer Mienfoo most of the time because of its ability to pivot in and out and check things like Murkrow and stall out sun turns with Fake Out, but Timburr has its niches over Mienfoo, primarily in providing a full stop to Pawniard, Carvanha, and more.
I don't feel strongly about Gastly dropping to C-rank, but I do believe that it belongs in B-rank. I think people underestimate how great Poison STAB is. Unlike Misdreavus, it's not really forced to choose among Hidden Power Fighting, Thunderbolt, and Dazzling Gleam because it can just run its dual STABs and then either Will-O-Wisp or Hidden Power Fighting to wreck Pawniard on the switch. A secondary STAB (that is strong(er than Shadow Ball)) is great. The only major cons to Gastly are its frailty, which is whatever for an offensive Pokemon, especially with its typing, and only 18 Speed, which admittedly does suck but doesn't keep it from wallbreaking. I'll test it out a bit more when I get the chance, but I believe that it's worthy of B-rank even despite Misdreavus.
I've never used Amaura, but I've also never struggled against it. No strong opinions on it, but I feel like it's an outclassed Snover and should probably just stay in C-rank.
edit: threw together a quick team around Gastly, and so far I'm loving it. Another thing that really, really needs to be emphasized about Gastly is that it's an offensive
Poison-type more than it is an offensive Ghost-type. If you just want a strong Shadow Ball, Misdreavus is probably going to be better for your team. But Poison is an amazing attacking type right now in LC because so little outside of Pawniard and Gligar resists it, and you still have coverage moves for them too. I'm trying Sludge Bomb / Shadow Ball / Substitute / Hidden Power Fighting @ Life Orb. At first I thought Substitute would be overkill on a Substitute attacker, but it allows you to set up a Sub against things that can't touch you (which is more than you would think with Gastly's amazing typing), things that you can force out, and things that rely on Sucker Punch in order to kill you. From there, very little wants to take either STAB or a coverage move from Gastly. Misdreavus might be generally more reliable as a Ghost, but as a Poison-type, nothing smacks around teams as hard as Gastly does. Here's a fun replay showing how amazing Substitute can be:
http://replay.pokemonshowdown.com/lc-73976176