You absolutely should look at code-switching and the triggers for that; you should definitely make sure that you cope with bilingualism; and i would highly recommend that you look at context-induced identity
1. Teach them to speak slowly. They start getting excited or thinking they sound good so they speak fast like a native and murder the pronunciation ( just like i do when I speak Vietnamese
2. Concentrate on the last letter pronunciation to each word this focuses them on the whole word.
3. Teach them tongue twisters to create both muscle memory for pronunciation and permission to make mistakes, laugh together, bond, relax and enjoy learning.
This may sound low tech but many years of teaching has taught me these 3 basics create faster learning.
Perhaps my first answer was too intuitive and quick. If you check my list of collaborative publications on diaspora-sociolinguistics, you will see that my perspective is more sociological than linguistics. I like conflict theories, in particular those related to cultural dimension. Hence, cultural relativism is important for me.
The suggestions by Skilton and Ladd are perhaps more relevant to your study, which seems to be focused on behaviours.
I would recommend a classic in sociolinguistics from which you could draw issues related to linguistic behaviours:
Holmes, J. (2008). An introduction to sociolinguistics (3rd ed.). Harlow, England ; New York: Pearson Longman.
I study different deteminants of intercultural communication from the perspectives of various sciences including sociolinguistics in Chapter 2 "Related work" and Chapter 3 "Scenarios of social interaction" of "Social interaction, Globalization and Computer-Aided Analysis". Please consult the library of your university for the full text. https://www.researchgate.net/publication/281644865_Social_Interaction_Globalization_and_Computer-Aided_Analysis_A_Practical_Guide_to_Developing_Social_Simulation
Book Social Interaction, Globalization and Computer-Aided Analysi...
Chapter Related Work on Social Interaction and Social Simulation