To clarify, I agree with your intentions, I just think the example you gave has some pretty big implementation flaws.

For example, people showing up at the end, when event E starts, will get bigger rewards than people who went all the way to event D. Sure you can find ways to fix those flaws, but it gets complicated. I just think you need a better scenario, e.g. one event that splits in two, and as the split happens, players who go back and forth eventually spend so much time running they're better off sticking with either event chain. Another example is if waves of foes hit all sides of a town at the same time, then there is no point to running from one side to the other, and in fact those who pick the less populated side get to have more foes to kill by themselves.

So yeah, I fully agree with your principles, I just thought you needed better examples.