It doesn't matter that Radhika would get married eventually to Dev. They wouldn't dare to show otherwise anyway. But it is the manner in which this story is taking place. Doesn't justify any of the adjectives like "spiritual love" or "divine relationship" or reincarnation of "Kanha" and "Radha". There is nothing in this kind of story that would attract somebody to this couple.
Dev saying "yes" to marrying Chanda (how else it can happen) knowing fully well that he is marrying a sister of a girl whom he "loves". Now Dev doesn't know Chanda and hence from his point of view she is an innocent girl. Why would you agree to ruin somebody's life if you can not go into that marriage with your heart? He is free to marry anybody. He doesn't have to marry somebody right now and that too Radhika's sister. If he says yes, it would be because Maheswari pressures him to do so. Not only he is a puppet, but he is willing to play with somebody's life because somebody told him to do so. Really bringing down his character if they do so.
Radhika: Will they show a switch off, switch on feelings for Dev? So she rejected him when she didn't think he was KK, ecstatic at the thought that her father would find KK for her and had no dismay that it won't be Dev, now happy again that the guy she liked is also KK, pursue Dev thinking that he is KK and her fiance. Will she again run away from him if she finds out that he is not Rohan and hence not KK? Will she then mop around and then pursue him again after she finds out that he is indeed KK. But then back out when she finds out that he is now engaged to Chanda. The last would be her reason not to tell Dev the truth about their marriage. So will she again let him go ahead with his marriage to Chanda knowing fully well that he is KK because she is obligated to Mansa and hence would do everything to please Shanti.
But then Kanha's leela happens and they have a switch and lo and behold, Dev and Radhika are married to each other. I neither see a spiritual relationship between these two and nor see them as people who fight all odds to get together. Where is the great love in this?
If Radhika suddenly does all the rituals and whatnot for Dev after she knows the full truth without caring for the society, does that mean she is madly in love with Dev and is willing to defy the society for that? No, it just means that her ritualistic nature has won and she would have done that for anybody who was going to be her husband. There is no love in this but just duty and beliefs followed in a particular society.
There is nothing in the story (if this is indeed the track) that would make one root for this couple. For this couple, unnecessary obligations, rituals and society's rules comes first and caring for others come second.