A beautiful Punjabi song against honor killings.

[Valar.]

haqeeqat to yahi hai janaab
saboot bhi samne hai

Sahi hai sirji, aap kehtay hain toh maan letay hain

 

[war&peace]

And yet there are cases of honour killings, judging of lovers by society and labelling them as bad/loose characters.

That's because people follow traditions far more than the religion. Very few people act upon the religion. They fear the society "log ka kaha ga"
There is no concept of blind arranged marriage in Islam. Both the girl and boy are encouraged to meet before marriage and talk to each other (of course in the presence of elders but still at a distance the girl and boy feel comfortable enough to talk). What I concluded is that the distance should enough that their normal voices can't be heard by guardians but both can be seen clearly.