1. It's designed to combine the words to from relations. Not a lot of words are needed because each added potential concept squares the number of existing ones. Any concept can be used with any other concept. All of your examples do exist in lojban, and are assumed to be from the perspective of the person saying it. Even so, they are terrible examples because they have no concrete definition even in English.
2. Those can be used with concepts. Traffic is such an abstract word it is actually a horrible example. None of those terms have anything in common. Traffic has multiple meanings and using it is like using Google Translate to speak professionally. You will never get there. The whole idea is to remove abstraction and you are bashing it for doing exactly that.
3. Hippopotomonstrososequapedaliaphobia. An actual word in English. What was that about long words again?
4. You memorized a lot more when you learned English. What was that about everyone being unable to learn new words?
5. Of course they aren't derived. It's not based on a single language. That would limit who speaks it.
6. You didn't find the parts because you were too strict in looking and didn't bother to look.