I don't know why sanaya said that she needs to be comfortable with her costar to create chemistry with him.Probably because she was comfortable with all her ex costars.One thing i want to tell u guys.There are many popular tv couples who never got along well with each other in real life.They were always at loggerheads with each other but their chemistry was awesome and people loved the pair.For eg.,Iqbal and Neha who played the leads in Kaisa yeh pyar hai.I had heard they wouldn't even talk to each other but they were so popular in those days.Their chemistry was awesome.Even now they are the most loved onscreen couple even though offscreen there would always be problems between them.I had heard that even Gurmeet and drashti had some problems much later in the show(i don't know whether it's true or not) but still they gave very good scenes.
So it's not about comfort.Actors who literally dislike each other can do many good scenes with each other and viewers like them then atleast there is no such problem btw sanaya and farhan.
I think TS edited few parts of sanaya's interview.Maybe they didn't show the whole thing.I am surprised sanaya will say such a thing.What's comfort got to do with acting?