Have you told them you feel pain in the liver area?
It might be worth making sure they do a liver function test (LFT) when they draw labs. It's not automatically done.
In terms of knowing whether things did the job, make sure schedule disruptions are factored in before abandoning Navelbine. You know.."leave no tool behind". (unless you're talking about exes)
How often are you getting Zometa? There is some interesting info on getting more than just bone met utility out of Vitamin Z:
http://her2support.org/vbulletin/showthread.php?t=39563