[The Radium King]

forget the light - the sensor is just a loop of metal inserted into the pad - the idea is that when the pad gets thin then the loop get abraded and opens the circuit causing the brake light. often heat will cause the sensor to fail when there is still life/thickness in the pads. VISUALLY inspect them. always. do not trust 50-year old tech with your life. i have just shorted the wires together and never use the sensors - most high performance pads do not even come with a spot to insert the sensor. you seem hands-on with your car, so just visually monitor the status of your pads and change when getting thin.

tips - don't let them get too thin, otherwise the pistons overextend and pull the dust covers off.

as other have said, don't change rotors until at minimum thickness UNLESS visual inspection shows cracking at the drill holes (s cars have drilled rotors) or UNLESS you change pad vendor - older rotors will start to form a ridge; move to a different pad that has a slightly different footprint and it may ride on the ridge and reduce your braking until things come to terms with each other.

if you do move to race pads (pagid, etc.) realise that they are thicker and do not work well with those anti-squeal thingies that stick to the back of the pad - if you put the anti-squeal thingies on a race pad you may get some dragging, heating, rotor warping.