I agree on the East vs West if we are aiming for orbital. I disagree on the speed being the same even at the surface, as (I think) you have to subtract the gravitational deceleration as you get from the surface up to the height of orbit. Coming from space you gain speed coming in, so this is not an issue.

Details aside, the overall conclusion remains that rail guns are not likely to be a useful means of propelling squishy cargo like humans into space.