The approach to take with this problem, is to break everything down into little steps and analyse them.

For example:
How to implement Alien NPCs

1. they function as part of an Alien Society

2. What are the fundamental principles of the society and social interactions that take place there. Ie. Sharing water on a desert world is a spiritually binding action.

3. The player can be part of the society, by the actions that they take.

4. But, how will they understand the outcome of certain of their actions?

5. Several approaches a. trial and error (but this would frustrate and annoy the player) b. Guidelines / training / observation.

c. give an example of the result and consequences of the action in English. This could be represented by an icon (with a tool tip in case they forget?).

ie. Helping workers = emphasises your solidarity with the society.