1) No, you won't see a bottleneck.
2) I don't think there's anyway to tell if the RAM/Mobo is DOA before you actually get it..hence "Dead on Arrival"
3) Great choice on the combo..it's actually a very sick deal
Be sure to get something with decent power phases for OC'ing! http://www.newegg.com/Product/Product.aspx?Item=N82E16813128519