I don't know if this capability went away with X2 or if I missed it somewhere. In X1 when your track layers got out of hand, there was rebuild layers or clean up layers, I forget, but I can't seem to find that in X2's lanes. So far I like lanes much better, but boy they sure can stack up quickly, and I may not want to bounce them all to one layer.

No, there is no clean up Lanes option, and I think it is down to the user to manage Lanes as required by deleting/dragging clips as you see fit.