I think dowry is not something where police will raid every marriage house enquiring about how much dowry was given/taken while performing the marriage, but it is a law that enables people to file a complaint after they are asked for dowry by the In laws, before or after a marriage. And when such law is implemented with full force and it also reaches the masses, then perhaps no In laws will ever taunt/beat a girl for not bringing dowry. It is just empowering women with at least some kind of weapon who were facing these same problems without any weapons to use before.
Regarding your story of police eating in the Shadi hall, I think this happens in any part of the world that police take advantage of people's violation of some kind of law and as a result police as a bribe either take money or resources from the violator. But when there is rule of law then you can just make a video of the police officers, or complaint against them for violation of some law and action against them will be taken. Remember police was never so much independent in the history of Pakistan as it is right now in KPK. I think even in the entire South Asia you don't find such a police which is free of political interference. There will still be similar bribery/blackmailing by these police(because there is no such thing as 100% corruption free anywhere in the world) but at least such actions are now not supported officially like in civilized countries...