Processing Implementations is about implementation of Processing in alternative languages, not about the implementation of our good old Processing. Moved.

And sometime I just get the generated Java file in the temp / tmp folder of my system. In my case, for my current system (Win7), it is at C:\Users\<login name>\AppData\Local\Temp but obviously it depends on your system.
A simpler way to get the information is to export to applet, since Processing includes the generated .java files.

Not for runtime errors, like the one you shown. Processing generates a .java file out of the .pde file(s), and adds lot of lines before the first (automatic imports, declaration of main class, etc.). So the line number you see in the editor isn't the one where you have the runtime error (unlike compiler errors);