1. Aahil is not Tanveer's son. Stepson.
2. I assume you haven't watched any episode post-leap. Don't watch random episodes and make up your mind. Or, depend on written updates, they hardly capture the essence.
3. Aahil is good to his sisters. Respects his family members. Loves his step-mom, and he should because he doesn't know what Tanveer is like in real life. He only knows that Tanveer took him blame on herself, hence he is indebted.
4. Aahil paid money for Dilshad's surgery. He did not want the money back. He only wanted Sanam to say sorry. He did not seek out Sanam for that either, It's Sanam who sought him out.
5. This is not to say Aahil is a good guy. He is not. He is flawed and a bit of a jerk. But he is not half as bad as people here are saying he is. If someone makes up a fixed image in mind, it's hard to shake.
6. And molested? No. Sanam has never been "molested" by him. The "dori incident" was a misunderstanding where she could have just easily looked back and cleared his misunderstanding. He thought she was his girlfriend, not some random woman.