-1. Yes, people read patents all the time. For one example many might be familiar with here, see any of the Mac or Canon or Nikon rumors sites, which comb through filings to learn what their favorite companies are up to. Second, the benefit comes not just from reading the actual patents. Since the info is already out there and protected, there's no real harm for those who developed the innovation in discussing it openly in journals/conferences/trade shows/popular magazines/newspapers/etc. We see this all the time, probably much more than if patents didn't exist.
1. Patents are generally written in pretty simple language. When they're hard to read, it's because the language used is technical, not legal.
2. This is just factually wrong. If you don't describe something, it's very difficult to try to prevent or collect from someone using the idea you haven't described.
3. Sure, for a limited time. This doesn't mean there aren't periphery benefits from seeing how someone did something novel. In the medical field, advances that utilize some novel technique often provoke other people to look at similar though unrelated techniques.
4. This is just factually and legal incorrect.