A superb post, the voice of reason, hats off.Everyone complaining about CRZ is, unfortunately, missing the point.
For the most part, CRZ are doing exactly what they were intended to do, and well: Create a more unified WarCraft community. They've increased and balanced World PvP on a faction v. faction level, and they've brought life to zones and servers that once felt dead. This is a GOOD thing.
The majority of problems you are experiencing are inherit problems with the game itself: Griefing, ganking, general player v. player harassment. WarCraft does nothing to discourage players from attacking characters that are a drastically lower level than they are. Some people like that (people who're a high level) other's don't (people trying to level lowbies), whether or not it's right or wrong has no simple answer, but it's clear the amount of ganking and low-level griefing has obviously risen drastically along with zone population. Maybe every town needs level 90+ guards, maybe there needs to be a kind of dishonorable kill system re-introduced, I don't know, but that problem does NOT lie with CRZ.
The same thing goes for questing, quest items, quest mobs, mining nodes etc. There is nothing to discourage griefing by stealing mobs, etc. It's easy to say "deal with it", but that's not necessarily the best response. (also winning the Stranglethorn fishing competition was never supposed to be easy, esp. on a PvP server.)
Cross-realm zones are essentially working as intended and you are experiencing World of Warcraft in the way that it was originally intended; a way that you may not have experienced in a very long time, if ever. You are now realizing that World of WarCraft itself, NOT CRZ, is broken. Hopefully Blizzard will address this on a GAMEPLAY level rather than just removing CRZ, because I believe that would be a huge step backwards.
Edit: Also to be fair, CRZ is a huge experiment and the level of data needed to determine how it would turn out is essentially unattainable without live testing. In order to bring everything back into order, as I said, they're going to have to make HUGE gameplay change, and I think that's a good thing. What we're experiencing now is a huge inconvenience, but a necessary evil. I view it as an incomplete improvement that is a sign of better things to come.