So, for number 2 and 6, I nominate the "survival knife". You know the kind, less than 20 bucks, has a hollow handle with stuff in it, sometimes accompanied by the words "special forces", Stainless Steel blade. Many newbies take it "just in case" and think it is essential. The fact that the blade is crap (too dull to do anything, and crappy steel so it won't hold an edge), the saw on the blade doesn't work, the handle is barely attached and falls off easily, will eventually show itself when it is needed and can't be used. We won't talk about the "survival" stuff inside. Some is good, and some not, but you could make your own little kit that works better and weighs a few pounds less.