Brian,
1) Lab difficulties range from 1 to 10. Typically speaking, what's the difficulty of the real CCIE exam?
2) Does IEWB R&S vol 1 and vol 2 cover all topics needed to pass the CCIE R&S?

Generally speaking the difficulty rating of the real lab will be roughly 7 to 8 as compared to our labs.

As far as covering the topics on the R&S CCIE lab the Vol I and II labs do cover everything you need for the real lab. In fact you should see more than you need for the real lab in these two products.