"Strangely, many native English speakers still believe they can do all things better than non-native speakers just because they speak better English. How long will it take for them to understand that they are wrong? They have a problem that they are not able to understand. They do not see that many non-native speakers simply cannot understand them. This does not mean the native speaker’s English is bad. It means that their communication is bad; sometimes they do not even attempt to make their communication useful to everyone. Often they don’t know how."
- A reasonable section of the book "Globish the World Over" which is also part missionary tract for a particular version of intercultural communication in English (you're supposed to learn to speak Engish with only 1500 words, and everyone uses the same 1500 words). (While this, like most other attempts to engineer a language, will fail, their point above is very true.)
Further thought: If you can, as a NES, master intercultural communication in this "limited" English, you will pretty much be unstoppable. Linguistic "pwnage" can still be yours. Don't worry.