In a sense yes, bankers and entrepreneurs are together doing all investments and my earlier comments on opportunity cost show that it doesn't matter WHO is providing the money, the interest rate gives the same incentive to DO or not do the investment if it is with borrowed money or your own money because the interest rate is for EVERYONE in an economy including the entrepreneur, it is as they say the most important price in the whole economy.

Your whole description of inflation and deflation in terms of 'pay in advance' vs 'pay after' is missing the point.  Every possible investment activity involves turning liquid money into illiquid goods and then back into (hopefully) more money MANY MANY times in the course of a year, ideally as fast as you possibly can.  The distinction of starting with your own money from savings or with loaned money is irreverent.  What matters is your internal rate of return vs your interest rate.  You must exceed interest rates to be considered 'a good investment' even if your self capitalized.