The flaps are not just one component, but multiple elements all working together. So it is hard to say when 'the flaps' will fail. It could be that the hinge pins will fail first, or some part of the track mechanism, or some bearings in the hydraulic actuators. Each one of these multiple elements will wear at a different rate.
Agree with those sentiments. Flap loads (on all parts) will increase as square of speed with a small correction for the effect of the aoa reduction that goes with the extra speed.
There isn't much out there on that subject - in fact the only thing I found was NACA TR 633, but that was published in 1938!
For what its worth that gives about 3% reduction in flap normal force coefficient for a 10% speed increase, so deploying flap at 160 KIAS instead of 145 KIAS would increase the loads by about 18%.
The effect of that on damage tolerance (and hence inspection intervals) would depend on the design, but is not negligible