Really? You seem to be advocating only casting Koreans as Koreans, Frenchmen as Frenchmen and Lakota as Lakota.
The world is changing. We had a Black man cast as a Norse god in Thor. Black actors are playing Presidents, Generals and businessmen.
Define "more alien".
Human playing humaniods? Is that really so hard to figure out?
I don't mind subtitles, but some people do. And it can get in the way of storytelling when used when not needed.
I've never said that only Lakota actors should play Lakota. I have no idea where you're getting that idea. It didn't originate with me. There is a great enough difficulty for a Native American actor to find a role now as it is.
Likewise I have no idea how what I said is any different that what you said. Ethnic actors shouldn't be limited at all in the occupations depicted in their productions. In fact we agree.
However life would evolve on other worlds, it probably is not going to look anything like us, nor communicate like us. It's obvious that human actors will be depicted as humanoid aliens. It's also obvious that more attempts should be made to consider the alien aspects of encountering other species. Cursory glances in any exobiology text always discuss this.
As a result of those profound differences, then the ships would likewise appear unique compared to our own.
I cannot understand the issue with subtitles. Some of my favorite films are foreign films. Nothing breaks the spell more than the universal translator always removing the extraterrestrial element from exploring space.