The answer to all of that is no royalty is owed. We’ll have a FAQ update soon saying no royalty is owed on prize winnings.
Your last bullet says distribution, and I’m not sure what you mean. If the prize is that the game gets distributed and sold, royalties are owed on the sales.
One exception is that if the prize is a nice bottle of scotch, you would owe me a 5% portion (or “dram”). J/k…