Is it considered a whisper (waswas) to think that Allah's saying: "To Him belongs all that is in the heavens and all that is in the earth" includes evil things on Earth, and what is the ruling on such a thought?

Everything in the universe belongs to Allah, and He created it with profound wisdom, not in vain. A Muslim should bear this in mind when reciting verses that affirm Allah's universal dominion and reflect upon the vastness of His kingdom. These thoughts that arise in the heart do not cause harm; they are merely whisperings (waswas), so it is best to disregard them.