As to weather machines, the atmosphere is immensely complex. Hell, we don't even understand how CO2 affects it, and we've been running that "experiment" for two hundred years.
Aso earthquake weapons. What about testing? I know many people say that these and those earthquakes, large and small, are results of testing of haarp. That these occur where earthquakes would likely occur is seen as a sign they're trying to cover it up. But think about it, if you want to test your ability to start an earthquake, you don't test that ability in the area with most risk of an earthquake starting anyway. How would you discern the effect of your weapon? We never how where and when an earthquake strikes anyway (we can only give probabilities). You don't give a guy sitting in the core of Chernobyl radioactive food to see if you can give him radiation poisoning....
You could perhaps start an earthquake unlikely far away from a fault line, but still you wouldn't be able to rule out the possibility of an earthquake happening there anyway. It's unlikely, but not impossible.