Ice shards can be good even if unattuned mostly on boss raids as there will be an ice lure there.ice is good for burst damage, most dps ice builds have firebolt as a 3rd dps spell, evades will ruin your life.
fire is good all around for consistent dps. Fire build does more long term damage than any ice build with equal gear
most high end fire dps builds run bolt/storm with a 3rd dps spell of incinerate or If your energy bar can handle it, you can run ice shards. Sometimes my un-attuned ice shards will still hit for over 6k.
with my hrung skull i can bolt/storm/shards/bolt with no delay between casts potentially doing a 25k burst which aint bad at all
In theory you could dump e shield and run firebolt fire storm incinerate and ice shards with the right gear, but even with 12k energy and 2100 esigs, i would be hurting. Incin doesnt stack either so no point in that at raids
Inc is better than ice shards IMO if u have the strongest inc on the fight.