My answer to question #1 : Prior to Livescope, most tournaments were probably won Spider Rigging (ask Capps & Coleman).
My answer to question #2 : I'm thinking jigs alone, in a Spider Rig setup and at Spider Rigging speed, could work .... but, I'm doubtful it would produce equally or better than with live offerings.
My answers are not based on "my" experiences, as I don't Spider Rig. My answers are based on information gleaned from this site & from experiences of a couple of friends of mine that are/were diehard Spider Riggers.