Under a scientific economy like socialism you dont need to be "apex male who exploits the workers under him to get yachts and tax breaks." The workers co-operate and thus the "apex predator" capital owner becomes dismissed the same way our towns and villages in the developed West don't pay fees to warring bands of gangs but instead we've unlocked the Republic and the system of representation and taxes and such via democratic action.

You absolutely can have utopian beings. In fact, I'd argue the greed-based societies get caught in the great filter and if there is a space faring race, its absurdly ethical and fair and, to me, explains the Fermi paradox. They're out there and maybe they see Earth but it would be hugely unethical to intervene here. The proper thing to do would be to only observe us from afar.

If this was a movie or novel maybe the Wow signal was them messing up, or a defector amongst their midst who disagrees with full isolation policies. But most likely it'll end up being something simple. The last good theory I heard was it domestic and was reflected off orbiting space junk, but who knows.