From Ice set I would skip Artic Air, Shiver and Flash Freeze. From Storm maybe O2 and Thunder Clap.
Don't skip Tornado. Ice immobs got a -knockback component which is ace paired with Tornado.
@False Fiction - Virtue / Defiant
Current projects - [Glaciologist - Ill/Cold Troller] [Cloudshaper - Storm/Dark Def] [Harald Wartooth - Elec/Psi Domi]
From Ice, I would skip Flash Freeze, either Shiver or Arctic Air (there's a bit of overlap, but you definitely need at least one of them) and probably Chilblain (although it can be handy for some extra damage before Tornado).
From Storm I would skip Thunder Clap and maybe O2 Boost (handy, but not a must-have).
CoX 50s: <ill/rad> <ice/ice> <fire/kin> <grav/sonic> <ice/storm> <earth/kin> <kin/elec> <cold/psy> <thugs/dark> <fire/dark> <dark/elec> <night widow> <EM/ninj> <mind/icy>
I think Ice/Storm are a very good mix together and it really depends on how u want your troller to play.
I tneded to have a simple killing area wher I would lay Ice Slick, Slap Snow Storm on a boss to keep them all in the middle then drop freezing rain on them for -def and let my team destroy what was there.
With that I found Thunder Clap and the AoE Hold (Not sleep which is flash freeze) very useful if the mobs wern't wiped quickly. Having said that in that kind of build tornado or the AoE Imob would have ruined my playstyle but are still great powers.
O2 boost imo is a gr8 team orientated power. It removes stun so can be doubled for when people use wakies or if a squishy has no mez. Hurricane amazing debuff and can give you some breathing room. Infact even arctic air is a great power. which i used a fair bit on the climb to 50 (But defo needs 3 end red slotting).
Of all the trollers I have played this one really locks them down and keeps them there with the combo I explained above.
But however you plan to play it have fun.
At the end of my ramble I'd say avoid Flash Freeze and i would say Gale but your forced to take it 
ok cool thanks for the advice i got alot to be goin on with .. thanks
Kin Hell Fire
Barline
Bibbi.
Slushy Kins
Nuria Dark
ah don't really need to mention this but an ice/storm controller is allot of fun to play 
just need some advice on wat powers to avoid >>
thanks
Kin Hell Fire
Barline
Bibbi.
Slushy Kins
Nuria Dark