Security is there to make sure you’re not carrying illegal stuff, as long as that’s fine, the only time they maybe check the id is before giving you the boarding pass.

Looks like the guy didn’t have a boarding pass altogether, so not sure how he got into the plane.

There is usually a person or an automatic gate that checks your pass before allowing you through the plane. However that’s more like a ticket check and to make sure people don’t get on the wrong planes, it’s probably not super hard to get around.

Yes, potato chips are completely fine in that situation. I don’t know why people say they have too much salt. Sure, they have a lot, but when you have a cold, you’re supposed to drink a lot of water, so that balances out. You can lose a lot of salt due to sweating (especially if you have a fever) and peeing. And salt is a very important electrolyte. And the fat and starch gives you calories.