Do you want an answer to your original question or do you want to try and argue that the stock market and currency move inversely?

Because if you want an answer, you aren't making changes to the example that will help you understand. You're introducing confusing factors that are not needed. The original example gave a neat little illustration of how wealth-as-measured can drop without money disappearing. Don't bring CPI in to it (and stock prices don't drive the CPI so that is a reasonable assumption).

If you want to argue that the two move inversely then go ahead and don't mind me, but you might like to add in some evidence or case studies. And you'll need to be precise about real vs nominal, and probably start modelling other effects.