As for how to host these topics without devolving into flamewars - I think you'd have to try a different species. Emotions get all of us.
I think the problem today is that people are unwilling to debate emotional issues, unwilling to have their own views challenged, and confuse their own emotional response to some topics with their own feelings of safety and well-being.
It is perfectly fine to have strong opinions, but because you hold a strong opinion does not mean you have to go to the grave with it.
Also, I am not really sure that there as many flame wars as people think. A lot of what people call "flame wars" are people attempting to trigger other people. If you get triggered by what someone says online, you only have yourself to blame.