"should" keep the pilot clear. It's still the PIC responsibility to remain clear of terrain, even in vectors off course. Pilot must maintain situational awareness.
Nope. ATC is never implied as a responsible party in any text or guidance from the FAA. Safe operations are solely the PIC's responsibility and if this lawsuit ever actually makes it to court the plaintiffs will soon find that out. This is akin to saying you caught your house on fire then blaming the wood becuase it burns.