I get where your coming from. Tbh, none of us are happy with the way this show is moving forward but that being said, I disagree with you at some points. Kunj back for revenge is seriously a cliched concept only seen in indian telly world. I agree that it will end up being opposite to everything Kunj as a character stands for but it's still better than Yuvi getting the girl. I am not against Yuvi but i just don't want such a character to get the girl even if he has supposedly turned over a new leaf. The show has always shown us that Twinkle and Kunj are meant to end up together and it will be absurd to have Yuvi paired up with Twinkle, who clearly loves Kunj just because of a misunderstanding.
Also, if Yuvraj does turn negative again then doesn't that just mean he was never totally positive in the first place? If he has actually moved on and accepted that Twinkle is Kunj's then why would he have an issue if Kunj and Twinkle get back together?
Even if she accepts to marry him, she'd never reciprocate his feelings. A changed Yuvi should be able to see that coming and if he fails to then we'll be back to square on.
About this being a youth centric show, let's be honest here, it ceased being a youth show ages ago. It's just another soap opera filled with baseless drama now.