Second question: This question is the same as above.
The third question: futures speculation lies in the word speculation, that is, speculation on the basis of spot. Like garlic, its price is generally higher than the spot. When the delivery month arrives, the speculators leave, and the futures price is the same as the spot. The price of the same thing varies in different places. Generally, the price in the place of production is lower than that in the place of consumption. For example, the price of vegetables in the south is lower than that in the north.
Fourth question: Again, only those who buy and sell can make a deal. If you don't sell what you buy, you can't make a deal. If you can't make a deal, there will be no such problem.
You are not kind! I didn't get a reward for asking so many questions!