<---------- (noob @ (fixed gear) bicycles and life in general)

I ride a fixed gear Surly Steamroller. The other day, the chain pops off my bike as I'm pedaling away from the spot where I fixed a flat. So I take it into REI (it was convenient, and the place I prefer to go was too busy) and the guy says the part that keeps the master link locked in place fell off, and they don't have one for my chain, so buy this $11 chain. He says it's a lot thicker (it's almost 3/8" wide as opposed to the 1/4" I had on there), so I ask him if there's a downside, and he says that it'll just run a lot noisier. This not being my hunting bike, I don't much care how noisy it is, so I say fine, and he puts the chain on there.

Riding it, I find that it's not just noisy, but kind of rough. So my question is, will having such a noisy chain on there hurt the cog or the chainring? Intuitively, I'd think there'd be more noise because there's more friction, and if there's more friction, won't that grind everything down faster? Also, if there's more friction, doesn't that mean everything's working less efficiently, and that I'm wasting energy/losing speed? I'm sorry if this is a ridiculously noobish question, or if it's been asked/answered here before. I did a forum search and didn't really find any answers. Thanks!