If you agree with this generalization, both the LOLB and the ROLB have the same responsibility in the passing game. If anything, the ROLB has more of a challenge in the passing game, because he will have coverage in greater space (generally, less players in the same space equals more empty space). I would put the better athlete, as opposed to size, or the better player in coverage at ROLB
I'll try to answer that, but someone please correct me if I'm wrong. When defending pass situations, we will be in nickel coverage for the most part. That brings in an extra DB for coverage. The weak side lb, should be rushing the QB for the most part.