As with any use of language, the word '******' being offensive depends on context. I don't think there's really any argument that can say it cannot cause offence since it absolutely can and most certainly will, there is no question there. The main issue with '******' in particular over many other words that are *clearly* offensive (ie. they do not have a usage that is not explicitly offensive) is that it has evolved in recent years/decade(s) to have two meanings and instead of falling out of the vernacular, it has stayed on and possibly even become popularised.
Like with other contranyms (such as 'left', 'rent' or 'screen') '******' has two opposite meanings. The first is the offensive one that is a racial slur. It is derogatory to black people and is loaded with connotations of historical mistreatment in America during slavery and pre-civil rights movement. The other meaning is a good, inoffensive one that equates roughly to bro, friend, mate, buddy, pal, homie, homeboy, main man, etc. In writing, the latter could be written as 'nigga' but in reality it is a different word that happens to have the same spelling and pronunciation.
So with one word that has two meanings, one of which is a racial slur and the other of which is a genial term for a friend (both usually used with a black person) it's a very difficult word to use. If intending to cause offense, then use it freely. Everyone will consider the speaker a racist and that's that, quite uncomplicated. If intending to use the second meaning, personally I can't see it ever working with a black person that isn't considered a close, personal friend. Calling a stranger '******' is almost certain to come across as the offensive meaning whether it's intended or not, whereas a friend will know it's meant genially.
As for another poster's question about the word "oriental", that's not offensive where I'm from (UK). I can't imagine why it would be. It's an adjective that means "of the orient" and can be ascribed to things as well as people (oriental food, clothing, rug, tapestry, spices, etc). It's no different than "European" or "British" in a sense, although the Orient isn't a strict, geographic place. Instead it encompasses the near-east, middle-east and far-east (pretty much most of Asia, minus the Indian subcontinent).