You are absolutely correct. There are biases that are handed down from generations. Especially in villages, lower caste folks are still discriminated against. As for the shadow part, my grandfather told me that was the case ~ 50 years ago. Things are not that bad now. Some folks (like my mother) are still stuck in the past. When you come home from the barber, you ae supposed to take a bath without touching anything in the house. Others are moving ahead with the times.
Especially in cities, anyone can go into any temple. We all rub shoulders with each other in trains buses etc.
I am not very knowledgeable about pre-partition days. But iy was and is still accepted that muslims make the best of friends and worst of enemies!)
IMO, at the root level, discrimination needs to be rooted out. That is the one thing that can hold us back. With education, other problems (even Kashmir) will solve themselves.
From reading your posts, I have known you as a progressive amongs Pakistanis. And have always respected your views (though I would like some softening of views in certain topics :))