Dude, are you serious?
Seems to me that what you are doing here is part of the problem. "Laowai" are not some new species of exotic animal, they are just people.Immigrants, tourists, foreign workers, and so on. That they are not locals is no fault of their own, and has nothing to do with being drunk rapists.
What you are proposing with this is really ugly. A suitable analogy might be something like the kind of internalized,reverse racism from the old days of the USA- "uncle tom" is the term, I think.
People are raped in Beijing and other cities in this world every day or every week, by every kind of person. It doesn't matter really where that person is from at all. Rape, not foreignness, is the problem. Why don't you write about that?
How many times does it need to be said, you are not responsible for other peoples' prejudices, and that includes the possible prejudices of certain Chinese nationals against whoever. If you are not doing bad things to people, no one has a right to come down on you for your skin color, 1st language, nationality, or what have you.
And most Chinese nationals get that, and therefore won't be prejudiced against you because of some drunk rapist in Beijing. And if they are, you should put them in their place, not apologize or call for harsher punishments for non Chinese. Are you a drunk rapist?
My guess is no. Have their been violent pogroms against laowai in china lately, with an event like this being the spark that could set of a powder keg? Again, no. So this has nothing to do with you or me.
Ironically, by acting the diplomat, you are adding to the divide that you are worrying about . Please stop.