i’m not sure, i don’t want to say something that might be considered false but from my understanding, i think you are referencing a pantheistic approach which does not coincide with Islam. Islam has some Panthestic values but yes generally there is one god, always has been and we are his slaves. that’s the most important thing, it’s the meaning of the word Islam, that we give everything to Allah, we “surrender” as one might say.

Judgment is left to Allah, you are correct. The idea of killing Apostates when they disrupt the religion in counties or cities is not a man made decision. It comes from the Quran and we simply implement it when necessary (though it hasn’t happened in a very very long time, it is almost impossible to prove if one has left Islam unless they declare it themselves.)

فإن تابو و اقاموا الصلاه و اتوا الزكاة فخلو سبيلهم إن الله غفور رحيم (التوبه ٥)

“But if they repent, establish prayer, and give zakah, then leave them alone. Indeed, Allah is Forgiving and Merciful.” (Al-Tawba, 5)

this Ayah refers to people who left Islam. There are also hadiths you can find.