2- If you are on r168 and exporting a universal app, you can use Construct 2's Browser object to handle the back button. It works natively now.
That's the problem, I tried using the browser's back button trigger, but it never fire. Instead, the app goes into suspended mode.
I did a simple test with a text object that displays a global value, a value which get incremented with each "mobile back button". Try as I might, every time I press the button (emulator or device), the app suspends, and when I resume it, the global value did not even get incremented.