So I didn't see the whole episode but only the second part on Desi-Tashan which had Kunj portrayed by Sidhant Gupta telling his doctor that his wife is in Amritsar and he needs to know about her ASAP. He also gives her name, Twinkle Sarna.
The other scene that was in the second link clip was of Twinkle signing onto the contract for wedding planning and then finding out after walking outside that it was Surjeet who had sent those papers through contract to get Yuvi transferred to Amritsar jail. Twinkle meets him and asks him why the Hell wouldn't he leave her alone. As of him initially and the his mother hadn't done enough to ruin her life.
These two scenes in particular reflected in the tracks heading the way they were since the track-change. For Kunj, Twinkle's happiness and well being is the first priority and the misunderstanding between them will ensue with her being tired of Yuvi's antics and just letting them go. He would want to get Yuvi punished as well. Another reason of misunderstanding would be Twinkle not finding him quick enough although the fact that she retained hope would help Kunj out in understanding her love for him in a moment of conflicting emotions of frustration and anger.
Sorry to say but the spoilers are not true in regards to Kunj turning negative. He'll be stepping back at finding Twinkle happy and make Twinkle reach out to him.
As for Anita and Yuvi; both are OBSESSED with Twinkle by through different motives and obsession isnt redemption.