I like your idea of Earthquake with Soft Sand to try and destroy potential fire types if they come in; nice edge! Ice Punch; okay. Now Swords Dance, a risky choice indeed.
Swords Dance will only work if you actually scare your opponent into switching out, but if they actually have something up their sleeve, they could just obliterate you since Abomasnow will take Fire attacks 400%. I suggest replacing this (preferably with Ice Shard), but if you like the attack boost to possibly pull off a sweep, why not? And of course Wood Hammer is a must!
First thing I noticed: Icy rock without Hail? A bit strange if you ask me; you should get a new item like Icicle Plate to boost Ice a bit or a Life Orb.
Now, you've got a pretty nice moveset here. Icicle Crash, that's a nice touch. Earthquake is there for obvious reasons, Reflect if whenever you get a change to set up. Not bad at all. But back to the item suggestion, you may want to consider getting Light Clay, which extends the duration of Reflect and Light Screen. Double Edge may not be so great. It is a normal type so you may not be able to hit much (such as Ghost types). If you are willing, I'd suggest Ice Shard so that you can get some priority and such!
Your Vanilluxe is a nice addition to your Hail team, with Light Screen and Toxic, I'm sure you'd make good use of this. There is not such a great movepool for Vanilluxe so you can't do much with it, but your is fine the way it is, so I have no suggestions for it.
A GREAT Curse user if you ask me. Although if you still want to go for the Special attacks, it's fine.
There aren't too many Special attacks Walrein can put to use so you may want to consider changing your Walrein as a whole.
What you have is a very standard set for a special user, so not much to it. Hidden Power [Flying] I don't understand. Could it be that it is for Grass types? I'm not so sure. You could get a Hidden Power [Electric] for variety, or [Ground] or [Fire] for a bit coverage. If your Walrein is ready and all, by all means keep it if it is stuck with [Flying]. I would get [Ground] for Fire and Electric types.
Again like Walrein, Cloyster has a very small movepool (tinier than Walrein's) with very little typing.
Your strategy isn't that bad, focusing on Defense so that the Shell Smash boost won't leave Cloyster with very little Defense. I like your idea of sweeping with this guy but to be honest, there isn't much to sweep with just an Ice and a Water type. Especially since Cloyster doesn't come with a lot of Sp. Atk in the first place. You may want to stick to the role of setting up with Toxic Spikes, and maybe even consider Spikes.
This Pokemon only has two moves, so I can only suggest so much.
Ice Beam, of course! (Maybe even Blizzard if you want to take even more advantage of Glaceon's exceptionally high Sp. Atk). Hidden Power [Ground], eh why not?
I would highly suggest making this Glaceon a scarfer though.
You could make it Timid nature (^Speed -Atk), with 252 EVs in Speed and of course Sp. Atk, with a Choice Scarf so that it could spam Blizzard/Ice Beam with a pretty decent speed. Glaceon isn't the fastest thing in the world, but you could make it work.
- Overall, good team! I like your ideas for moves and all, and I wish you many successes with this team.
I'd rate this team a 9/11!
Also, note that all EVs are maxed at 252 per stat and not 255.