The reverse is true, in that the arcs represent the wanderings of the aircraft.
No, the arcs don't represent any 'wanderings', arcs are arcs and they fit well with the assumption that aircraft continued on a fairly straight path. If the aircraft was doing some 'random' turns that arcs would look completely different. I believe even the ATSB report mentioned that.
he was "confused and angry"
These people would always be 'angry' no matter what happens and who says what. I believe there is only one scenario in which they would be less angry - if someone miraculously finds the aircraft with everybody alive.