"after an RTO or landing, (two different types of events-one an abnormal-the RTO if my english serves me correctly-the other quite normal-landing) if either thrust lever is advanced, the SPEED BRAKE lever automatically moves to the DOWN detent and all spoiler panels retract. Ther spoiler panels may also be retracted by manually moving the SPEED BRAKE lever to the DOWN detent."
As a non flying type I can only give you the way I understand the system to work.
The reason for fitting a system that moves the speedbrake lever (and so the spoilers) is not RTO but rejected landing. Theory being that speedbrakes are armed for landing, deploy on touchdown, "oh s***! who parked that on the runway?" throttles to max TO. You don't want to be trying to get airborne with speedbrakes deployed or trying to stow them manually.
You will also find that they deploy automatically as you apply reverse thrust during an RTO even if you haven't armed them.
Its been a while but I remember being able to test the config warning horn just by advancing the throttles with engines running or not. In fact it used to be a test carried out during the "Daily Check". If you are not in TO config and you advance the throttles the horn will sound. The CB is pulled during high power engine runs to stop the noise as we don't tend to extend the flaps etc.