2. They are _American_ staples. They are not necessarily staples in receiving countries, and as noted above, may actually be distorting local markets and foodways. I would also argue that subsidies for American farmers should _not_ be applied to export crops, as noted above.
3. Not tangential at all. America could divert a small fraction of its military budget into meaningful wage subsidies for farm workers that could make farm labour more attractive to more people. America spends more money on its military than the next ten biggest military spenders in the world.
Yes, I exaggerated that a single F-35 could provide this sort of subsidy. My point, however, stands.
Food production is a modern solved problem. The politics of it is not.
No country is giving up food security and voter messaging to the invisible hand of a global market. No one likes corn as much as Americans do, yet its one of your greater exports, simply because of American economic and diplomatic ascendancy.
#2) The US isn't just a net exporter of food, its one of the dominant food producers (in exports) in the world. A country like Canada only became a net exporter of food in ~2019. These US exports are primary stables like corn, beef, pork, etc.
#3) f-35 funding is tangential to the conversation. bringing it up only makes you sound un-informed and polarizes your argument for the issue at hand.