I am very much impressed by your research and analysis,  to answer your last question in the west it is common for punabi and south Indians to marry but a portion of the sikh residents in west are new immigrants whose family still reside in punjab and their openness is narrow regarding interfaith and intercultural marriage .

Having said that , update is that my partners dad is currently looking to break her so that she listens to him. His ideal expectations of her is eventhough she is 29 years old and has strong emotions towards me  she should let go of me and happily marry a person he finds for her. And there is actually no neutral party in the scenario who can bring him to senses so that he can talk on some logical term such as my character,  job , values , family.  For now since we’ve run out of ideas , we will stay quiet and continue with behaving normally with him.