Sogi-Ya: the Dirty Irish mobster
Badger, the mobster in question, had a cockney accent. He was not Irish.
Sogi-Ya: the Miserly Jew torture addict
There was nothing in the show that distinguished him as Jewish. That's your own assumption.
Sogi-Ya: the psychopathic space-n-word threatening to rape the spunky white southern girl
I think you're bringing in your own psychological baggage. The character you're referring to, Jubal Early, was a bad dude but there was nothing race-specific about the character as written. He could have been played by anyone. It just so happens that the best actor for the job was Richard Brooks.
Sogi-Ya: the worst was the "Marauders" (or whatever the fuck they were called) being stand-ins for an Indian raiding party
The Reavers served a similar narrative function that Indians often serve in westerns (or the undead in zombie films). There is no racial element to them, they're made up of people of all races.