I’m wondering if they cost the pads at the factory to prevent corrosion or something, then as they start to get warm that coating cooks off.

Just a guess tbh.

While running? Likely an alternator.

1. Theoretically, as long as the fluid has not absorbed any moisture, it would last a long time. I would assume that over time the heat would degrade it somehow and require it be changed. That being said, it’s going to get moisture eventually.

2. I personally think doing both is needed. The point of flushing the fluid is to remove that old, contaminated brake fluid. In never cars with ABS modules, there is more fluid than you would think in the lines and module etc. so just removing the fluid in the reservoir does not actually accomplish the goal of flushing it.

2a. I suppose you could do this, but what a waste of time. Why not just crack the lines and do it properly?

3. I’m sure I’ll pay for this comment, but I have never torqued a bleeder screw. I’ve always used a small wrench and just made sure it’s tight and not leaking.