1. Do I need to compile an APK and sign it / zipalign it to make it work? Or should it work by directly playing the .zip file using Ludei's testing app?
You only need to compile it to APK using Cocoon JS
Dont forget to set it to 1.4.7 compiler since 2.0 is not working
Also, don't minify it
2. Will the ads show on a game which is not published on Google Play but is in beta release in Google Play Console?
From my experience, the ads only showing up in the compiled APK
3. Also, can you just explain how to add events for full screen ads?
Mainmenu event sheet
When touched Play -> Go to Layout Ads
Layout Ads Event Sheet
In in CocoonJS -> show full screen ad
System: Wait 5 sec
Go to Layout "Start Game"
Should it work? I want it so that when player touches Play he is shown a full screen ad for 5 sec then he is redirected to the main game.
Theoritically, it will work