Vivaan is completely justified in the way he feels. Suraj and Imli need to realize that after the relation they shared you cannot be having these type of hugs or conversations like they had in the car. I am sure had the roles been reversed Suraj and Imli would have reacted the same way, infact it already happened with Imli!
I totally agree with you. Chakor and Vivaan have already done so much by accepting them with their past. Is not easy. Everyone who claims differently is lying to himself. And especially Vivaan. He accepted a girl with a past in an Indian society and that too into a village. Not to mention that the girl's past is his own brother. In return to all of these, Suraj and Imli can give them at least this: no reason to ever be questioned again about their past. I know it was a friendly hug, but a little effort from their side to avoid awkward situations will be very much appreciated.