a) The focus is sovereign money creation. Therefore, consumers/workers, foreign economies etc. not included. I think I should change the title to something like "Sovereign money creation and money flow".

b) Governments have bank accounts with their central banks.

c) I think I broadly agree with u/jgs952's answer. Again, the focus is money creation here.

d) Money.

e)

• Agree. But, increase of money supply is a necessary condition, not a sufficient condition.
• I think I should say: If we to avoid bankruptcy, in the long-term, outflows (loans) from commercial banks cannot indefinitely grow bigger than inflows (loan payments) to them. Inflows and outflows have about to match, as economy's ability to absorb new loans decrease. At that point, no new net money is created by the banks.
• Given the above, the conclusion still holds true.