You might want to wait until one of the forum heavyweights chimes in (haha), but for what it's worth, I'd stay put.
Subban is a beast with your stats (he is anyways, but with hits and PIM he's 10x better than Ehrhoff), and if you got Smith in return, I'm not sure it's a big enough upgrade over Backstrom (especially since Smith has been pretty stinky so far) to warrant moving Subban.
Since it's a weekly start league, I'm not sure how much value you'd get out of Fasth (all depends on how long Hiller is out/if Hiller picks it up once he returns). That being said, I'd drop Varlamov over Backstrom and who knows, maybe you could trade Fasth to the Hiller owner.