RMP Questions are becoming quite popular.
Okay, Go for Life orb Over Either of Those, pretty much the only time to use a Type effectiveness plate is if you have Double STAB ( Example. Mach Punch Focus Punch = Fighting Plate Opurtunity ) And Although a 436 max is nice, Going with the Life orb gives you that extra punch to finish your opponent off.
Ice Punch works well, and I have to agree they should've given him Avalanch :'(
As Far as Brick Break is concerned, I personally think " Super Power " Would work better.
Being a Revenge Killer, he kills and Switches, Super Power Gives you that extra packing punch, and you can just switch afterwards.
Use Return, as Water + Normal gets awesome neutral coverage.
As Far as Nature, Adamant works well, And The Ev's Look fine.