Question regarding Man, Economy, and State, about changes in the structure of production

Economics Economics Questions
1

In the chapter 8.2 on the changing structure of production, Rothbard discussed the cases:

  1. where savings increase and the interest rate falls
    and
  2. where savings decrease and the interest rate rises

He describes the effect of net investment (or disinvestment) on the structure of production. This explanation is amazing and really helped me. But I wished that he would have continued to explain the cases of:

  1. where savings and interest rate both increase
  2. where savings and interest rate both fall.
  3. where savings changes but interest rate stays the same
  4. where savings stays the same but interest rate changes

Those cases are surely possible, because earlier in the chapter on interest (chapter 6.3) he showed how both the amount of saving and the interest rate are both determined by time preference. In cases (1) and (2), he is really describing a shift in the supply schedule (of present goods for future goods). I would be interested in a discussion, like Rothbard’s, of what would happen if there was a shift in the demand schedule, or a simultaneous shift in both.

For an example, case (3) could occur if the demand for present goods (in exchange for future goods) increases. The increased interest rate would result in a steeper slope in figure 61 which usually refers to a shortening of the structure of production. But this would coincide with net investment and thus increased productive capacity. And the two seem to be in conflict.

Can anyone help me out? Or point me to an explanation of this or point me to someone (e.g., an economics professor) I could ask?