I think this is one side of the picture. participation may lead to ending of misconceptions different sects have about others. Moreover, if people learn to respect what others respect (point 3), then such participation would make others not to indulge in acts which creates hatred.
I would quote here example of Sham e Ghareeban Majalis as telecasted from TV. Aren’t these watched by Sunni majority? Do they say stuff in these programs which offend Sunni viewers? No.
So everything is possible, if there is a will in a society to move towards solution.