Because of the way Ice types are made, they are incredibly bad defensively and amazing offensively. However, Gamefreak makes most Ice type walls, making it a very poor type, and one with little variety. You can totally pull off a Mono-Ice team, just that Mono-Ice teams perform better the closer they are to Hyper Offense. :P
I find Steel Monotype teams to be very common in the upper 1300+ of the ladder (and beyond), and they are usually the biggest threat to Mono-Ice teams. :P
Abomasnow is a bad choice in general, but Especially so with Mono-Ice. Most Mono-Ice teams don't use a Mega Evolution because all Ice-Type Mega Pokémon are garbage. Use a different Pokémon, like Weavile. :P
Ninetails isn't likely to need Hail to set-up Hail, and Hail honestly isn't that great to merit a move to summon it. You'd probably need the Dark Coverage Moonblast provides more. :P
Kyurem-B needs Fusion Bolt to effectively harm Water types and Steel-Flying Types that your team may have problems with. :P
Sandslash doesn't need Aurora Veil (and shouldn't risk a turn set it to begin with), and would benefit more from Swords Dance or Iron Head. :P
Just some probable advice, although, I could be wrong. Hope I Helped! :P
