Strafe: rolled attack number doesn't count against RoF, and Strafe shots are considered simultaneous attacks (as per Legion Theme Book).
Thus abilities on the models hit (like Sacrifice from the Exemplar Errants or Tough etc.) only trigger/getting resolved AFTER all Strafe shots are made, just like under Spray- or AoE-template.
Strafe-targets still have to be in range of the ranged attack or the attack will automatically miss.
Field of Slaughter (feat) gives an additional die to attack rolls. So you still can add another die by boosting if needed.