Sorry, but your opinions of Cyrus are not based on fact.
Sure, you can make an argument that empires have an incentive to avoid uprisings by not being overly oppressive. This was certainly the approach taken, most of the time, by the Achaemenids.
But they were unusually mild by imperial standards of the time. The Assyrians felt an incentive to discourage rebellion by terrorizing possible rebels, which they went about with great enthusiasm.
The Assyrian and Neo-Babylonian Empires both deported Jews to distant lands. The Persians, OTOH, not only didn’t deport more Jews, they allowed the exiles to return home. They had no need to do that. The displaced Jews were not likely to rebel.
It is difficult to avoid the conclusion, IMO, that Persian policies were at least in part based on altruism or humanitarianism. To a degree unusual in history. Certainly this is the point of view of the Bible writers, who speak much more highly of the Persians than of the Egyptians, Assyrians, Babylonians, Greeks or Romans.
As far as all these faiths living in perfect peace until Islam came along, that’s a myth.
The persecution of Zoroastrians, Jews and heretic Christians by the Romans and Byzantines is pretty well known. Less familiar is the fact that the Sassanid Persians probably equally persecuted Christians, Jews, Manichaens, Buddhists and others. This intermittent persecution ended only when they were overthrown by Islam.
http://www.fsmitha.com/h1/rel-zoro3.htm
But compared to what we are dealing with NOW with Islam, the examples in question will look small.