um..i'm very vague on interpreter...(haven't read it since feb 2011!) So, i will try to help out where i can...So, in regards to relationships fraught with difficulties...
the first story, with shumukar and shoba...you can see that their marriage was once very happy. I think it's symbolised by their cooking. When they were happy, the dishes that they made were lavish. their relationship was once very joyful, full of laughter and stuff. However, after the stillborn of their child, things changed. They no longer communicate to each other--like Shumukar would go up to his study for dinner, and Shoba would be downstairs (or something like that. Their relationship turns into experiences of hardship, alienation and the inability to communicate.
um, the story where the dallas family goes to India...interpreter of maladies? i think that's it. you see tht the relationship between the members of the family are also very distant. the parents act more like "teenagers" to the kids, rather than actual parents (you acutally get a quote on this from the narrator himself). So, in this story, you can tell that the relationships are also very difficult. Mrs Dallas finds it difficult to communicate to her husband: she confesses that she's kept her infidelity from him for all these years. you can even go on talking about how American born Indians have a difficult relationship assimilating or fitting back in and understanding their own home country. I remember thatMr dallas takes photos of poor men as though they are "sights" to be seen in India. He doesn't look with pity or sympathy, but rather as though the poor of India are just "items."
In terms of the actual essay question itself, where it says that "ALL" relationships are fraught...etc....you can argue whether this is true or not. Perhaps you could take a different approach, saying, yes, all the r/ships are difficult, but it is this difficulty that helps the characters realise that communication and understanding are significant to their lives or something like that. LOL.
Point is, just brainstorm...and see what you can come up with that not only agrees/disagrees with the topic, but takes an interesting angle.
I hoped i helped!