Answer:
1. It is important because the patient will not want his personal details to be leaked to strangers.
2. Advantage is easy updating of info or filling up of forms, well there are other lots of advantages. The disadvantage is if it somehow gets leaked or someone has the hospital or clinic's database.
3. It could be used with malicious intent, or to threaten the patient with the shared record.
4. Yes, they need to be held responsible. Maybe removal of license is the worst, reducing the salary is the minimum.