>> Could I make the app first in windows and when I am ready to export it to mac I just open the same file in a Mac desktop and export it from there?
For basic functionality, yes. But note that iOS specific features such as notifications, in-app purchase, ads, and many iOS specific plugins are not supported in the simulator on neither OS X or Windows. You have to test on a real iOS device. And for OS X desktop app testing, it’s best to test on a real Mac. Just like Win32 desktop app testing is best done on Windows. That’s why our Corona Simulator is called a “simulator”, because it’s meant to be a close approximation, but it’s not an actual hardware emulator.
Also, our Windows Corona Simulator has some limitations. It does not support native WebViews and VideoViews.