Sunflower seeds go rancid fairly quickly if exposed to air.
Peanuts last longer, but will still go rancid.
Yes, I know peanuts will go bad but I think them lying out in the sun on hot sand may have preserved mine as none went bad in two or three years.
My Uncle Buck whose field it was, used to keep a large hamper full of peanuts just for eating. All his family and for that matter, ours would just scoop up a handful whenever we felt like it. His only had to last until the next harvest. I don’t ever recall that hamper running out.
Not if you plant some. You could have a continuous supply of peanuts with little effort.