I've read enough posts from people who have encountered trouble while carrying knives to know that:
1. Doesn't matter what the state or local laws are in this country or elsewhere, if the cop on the beat doesn't like your appearance or your blade, they can haul you in and make your life miserable.
2. Be understated. Carry more than one knife or a knife with more than one blade, and use the smallest possible blade for every chore. Don't use your survival machette to open a package of peanuts.
3. Don't make a big deal of whipping out your knife for a chore. Deploy your knife quickly and quietly.
4. If you look disheveled or unkempt, you are much more likely to be eyed with suspicion. If you dress and act like a civilized human being, you are likely to be treated as such. As far as the local police are concerned, you CAN tell a book by its cover.