i'm new to the lore and i have so many questions

i have a habit of getting way too into the details and worldbuilding with new games, especially future sci-fi ones like destiny, and i need answers for the things my brain can't ignore like

1. if guardians are reanimated corpses do they need to eat or sleep? obviously they CAN eat, cayde does, but that also brings up
2. do exos need to eat? instead of sleeping do they need to charge?
3. do GHOSTS need to charge?
4. if your ghost dies or gets destroyed, what's the procedure for getting another one? is it even possible to get another one since the ghosts are chosen specifically for each guardian? are ghosts basically the most important but simultaneously the most fragile parts of every guardian's life? no wonder they spend most of their time dematerialized in your pocket
5. how many times did humans try to send space nukes at the traveler before realizing it gave them magic? we all know they tried at least once

i've only played destiny 2 so far and i'm not completely finished with it but these questions can't wait

i'd love to hear theories and/or places where the game answers any of this