What is that saying that some police have? "You can maybe avoid the rap, but you can't avoid the ride." In other words, you may not be guilty of anything in the end, but they're going to make you miserable up until that point.

You are planning to visit a US city where politicians have little common sense, and they have enacted some really draconian laws. I would apply your own common sense instead, and just leave the knife at home. It's an embarrassment to some of us that we have a few cities like this in the US, but unfortunately, we do. There are many fun things to do in NYC (trying to understand the politicians/government is not one of them). Have a great trip!