a - Variation is natural, normal, and continuous, and ELT professonals must establish a tolerance and understanding of variation
b - Prejudice against varieties is likely to occur
c - the differences between all varities, both native and nativized, are similar and comparable
d - the specific teaching and learing contexts and specific needs of learners in those contexts should determine the variety to be taught
e - multilingual non-native teachers represent ideal teachers in many ELT contexts.
I strongly agree with (e) and wonder where it leaves me as a monolingual native teacher. As I think about my future career, I hope I'll still be "in the trenches" at least part of the time, actually in a classroom teaching something to students who want to learn English -- but I'm not sure what my role should be. Right now I feel like I can do the most good as a mediator between the Chinese educational context and the North American one, but when I think about the "humanitarian" side of ELT (if there is one - it's hard to say), I sometimes think helping elite students get into elite universities isn't my ultimate goal. I'm attracted to the idea of teacher training for local English teachers in "less-deleloped" areas, but when I think about that the ghost* of Robert Phillipson starts moaning in my ear about imperialism.
(*He is not actually dead)