Mesh if there is no love triangle then how Karan will separate Sukor? It will be silly if they separate from some stupid and not so much important reason?
I think Karan will be after gold idol and once he finds out about Imli trying to harm Saanvi he will help Sukor so no one doubts him when golden idol goes missing since he is only new person there. If he finds out its Imli maybe he will get angry on her for hiding that idol. I think there was some kind of deal between them which wasn't fulfilled. After some time when he tries to steal idol or maybe do something else Sukor will break some of his plans or maybe find out about him which will be his reason to shake hands with Imli and starts working against them.
I don't know how Sukor separation can fit in all this. They will have emotional scenes between Sukor every time Imli tries to harm Saanvi, maybe a little blaming but nothing big, they will deal with mansik bandhua, then there will be Karan and Imli and how they know each other or are yet to know. If Sukor separate they won't be able to concentrate on other things as much, which are needed to be explained or dealed with.
There is a reson why Imli is happy for discovering that Chagan is not happy with Chakor and she will use it. But even from the answer about Saanvi it's clear she does not have intention to kidnap Saanvi and goes away from village. She wants to stay to torture. For that to be possible she doesn't need complete support from villagers but she needs them to be less on Sukor's side. And maybe she will not turn them against Sukor but she will brainwash them so they are less willing to help them at least for some time. She said she wants to threaten Chakor kidnapping Saanvi and I think she will somehow clearly said to Chakor who she is but villagers and maybe even Suraj won't be able to belive Chakor. I think first time she kidnaps Saanvi she will be overconfident but Karan will save her. I think it will be revealed that old lady tried to kidnap her that will mean she will have her third look which will be last one. After that it's she working with Karan or she fearing him for sometime but still determined to harm Sukorvi.
If Karan is after gold idol and there is absolutely no kind of revenge from his side to Sukor yet then he doesn't have any reason to separate them. Even later when he becomes against Sukor separation won't fit in his character. I think he is charming thief but he is not cunning. He will try something concrete to harm them and maybe that time Saanvi will be under bigger danger and maybe she will be separated from Sukor for longer period which is enough for emotional scenes between Sukor without separation.