Don't your "snacks" have to go thru security? Don't things have to be in original wrappers and unopened? How can you get thru airport security with things stuffed under/in your coat? ???????
yeah, but the problem is how much your carry-on weighs. yeah, it has to go through security, but they don't care how much stuff you have. only that it's not a threat to security.(and I think the original question was worrying about baggage getting lost).
lots (but not all) places won't let you take more than 10x 100ml of any kind of liquid, and nothing that could be a weapon, so no blades of any kind (including nail clippers), but homeopathic remedies in pillule form, herbs in herb form (not tinctures), books, BP cuff, fetascope, medications, etc, you can take as much as you want through security. they might have a look at your stuff, but it won't be an issue.
As to snacks, I've always brought loads of snacks on planes (I travel with a little kid), and they never care if the packages are opened, as long as it's not liquids (like juice - and that you can't bring whether opened or not if it's in a bigger than 100ml container). that said, i've never flown in the US, so I don't know what their requirements are. they're all arbitrary anyways. Israel, which has way more security than the US could ever dream of, allows people to take liquids on the plane (no doubt because they know that the "no liquids on the plane" rule is bogus anyways).