The lab is a temporary area, you don't get to access it again. Right now, I'm focusing on adding multiplayer and releasing the game as it is, not additional post-ending content, but I'll keep your ideas in mind for potential post launch updates. For earth, you cannot end the meteor shower (some players suggested a moon-quest where you could stop it), but they do not harm buildings or tiles, and can be blocked completely by walkways (unlike bombardment, which breaks walkways). Once you deactivate the drones, they will only attack if they are damaged and malfunctioning - if you aren't attacking them, and they aren't being hit by meteors (protected by walkways), then they will be docile.