Well, respectfully, if you have been watching wrestling since the mid-60's, you have either not been paying too much attention, or you were REALLY confused 15 years ago, whereas now you are only gently confused by the ruleset, because things used to be MUCH worse.
1. The point of international wrestling isn't pinning, it's turning. They have the pin on the books, but it is borderline outdated. The pin could be removed from Freestyle and Greco and it wouldn't change anything.
2. The replay happens on a matside monitor that they record with matside cameras (I believe). If you are in the arena you can see it, I have never seen a remote broadcast where they show you the actual footage they are reviewing.
3. The shot clock is a tiebreaker system they have implemented which exists to drive action and make it so that guys don't just hang out and wait to score in the last 30 seconds. It is close to stalling, with the added nuances of understanding that basically, the ref has to choose someone to hit first, and if things continue, the second guy will get put on the clock. With the last point scoring giving criteria, being put on the clock first is a good thing in a slow match.
4. Like exposure, takedowns are about achieving a position, not achieving definitive control. I don't know all the positions by heart, but for instance, the high crotch crackdown is a takedown in freestyle within certain bounds, whereas in folkstyle it never is.
5. That might be a bit of an overestimation about most fans not understanding...but if you are looking to learn, this is a good place to ask specific questions.