Deen isn't culture. It's a filter for culture, which means Deen is a codification of fitra. It gives you access to fitra. It gives you a way of understanding what your intuitive sense of right and wrong is and what is appropriate in the moment.
The meaning and the significance of the hadra is that it is like a shaking loose. It is a shaking loose of the things that normally worry you. It is like letting go of the chains so that you can find out who the being is that is there beyond the chains.