I've US bachelor's degree. I also have 5 yrs exp. working as QA. I worked as consultant for 2.5 yrs with comp A. After that, I joined comp. A as FT and have been working for 2.5 yrs. Comp A has already filed my GC under EB3-ROW with PD of April 2010. My I-140 is currently "pending" with notice date of July 2010. I'm thinking to join comp B (consulting) and apply under EB2 as QA. My 6th yr of H1 is expiring on 9/30/12.

1) How safe is it to join comp B given that, EB2 with consulting comp has now much stricter scrutinies?
2) Do I need to wait at least 180 days after my I-140 approval before moving jobs?
3) if I move to comp B, would my H1 gets extended beyond 6th yr? Or, should I not worry about my H1 extension since I can get EAD once I-140/485 are applied?

Thanks!