Hang-gliding and Paragliding are, so far, NOT regulated by the Authorities in our country. We fly mostly out of public uncontrolled land. Therefore though the card is welcome, it is not mandatory. It is a good mean of introducing visiting pilots to the local "coaching" pilots.
In practice, nil/undefined. However Civil & Penal Law applies. In case of damage to property, the pilot at fault will be liable to pay damages.
It is up to each pilot to decide on the coverage he requires.
Please refer to our comments above.