Just to put this out there as well, as I don't believe it was touched on in any of the replies (sorry if I just missed it, but it is actually in there somewhere!), but one reason for choosing the ice staff for your back bar is that the destro staff passives allow you to reduce the cost of block and to increase the amount of damage you can block while using an ice staff. This, in combo with the already-mentioned Wall of Ele skill putting your full-strength Crusher debuff on boss/mob, is why you see the ice staff as the back bar weapon for tanks so much.
I am all for not having every single char have to follow a specific meta, so by all means make whatever char you want! However, it's also good to know why the meta is what it is, so that you understand the costs/benefits of anything your tweaking for your own personal preference
The meta changes from time to time, anyways, so it's not crazy useful to be married to any one specific way of doing things on all your chars. I'm an altoholic, so I have variations on damn near everything.
BUT! As I said, the ice staff, other than the sword/shield, is really the only place you'll get weapon skill line passives that really beef up blocking amount and significantly reduce the cost. With the changes (a while back now) to how blocking will drain stamina (ticks once every quarter second, I believe, or half second), it's quite useful to have the reduction in cost, for those (probably many) times when you need to block and don't have the time to swap back to your main bar.
Just throwin that tidbit in there for (hopefully) useful pondering!