Requires understanding of integrals

Actually, I'm not sure it does. You seem to have gotten through to a couple of people on the strength of your math, but one way of wording a critique I see repeated in the comments is that there's no such thing as the "instantaneous annual value" of self-improvement in the real world. I tend to agree.

What was your intention when you decided to compute the instantaneous annual value of different strategies? Sometimes it makes sense to let a model deviate from reality in order to make it simpler, clearer, or more tractable. I don't see how your model accomplishes this. On the contrary, it seems to me like computing the value of different strategies on an instantaneous basis complicates your model by requiring the use of integrals.

A model that confined itself to calculating the net present value of a finite # of months or years of various strategies would have been both (a) more accurate, in the sense of better reflecting real-world concerns, and (b) easier to understand, in that it would have required less math.

I do hope you publish the 'practical' half of your article, but I urge you to be careful not to let your ability to do math get in the way of your ability to develop and teach useful models.

You also may wish to avoid mimicking the formal style of textbooks, e.g., "exercise for the reader," "question to confirm understanding." This tone of voice can be easy to use, but it's odd and unpleasant for me to read it, given that (in theory) we're all peers here. You may have something to teach us, but you're not exactly my professor.