Any book can be incorrectly translated. But with the texts in the original languages still there for anyone to study, I don't see why that's a big deal. It certainly doesn't put the Bible into any special category of being inaccessible or corrupted relative to any other books.
Most of the rest of what you say looks like baseless conspiracy theory. The Nicene Creed had nothing to do with the making of the Bible. I'm not sure what you mean about writings being thrown out or discarded, but we still have all the scriptures that Jesus and the apostles read as scripture in what is today known as the Old Testament, and the ones they passed on to the Church for her permanent use in what is today known as the New Testament, in forms that are in all important respects no different than the forms they took in the first century. If some people choose to discard any or all of those books from their own use, that reflects on them, but not the scriptures.
The Hebrew word used in Exodus 22:17 (verse 18 in English versions) is mecashephah, meaning "one who practices sorcery," from the verb cashaph, which means to practice sorcery. Three centuries before Christ, and 19 centuries before King James, it had already been translated into Greek with the word pharmakos, which also meant one who practices sorcery. It was also translated as "witch" in the English translations that preceded the KJV.