I didn't had much contact with supervisors but only because i'm really autonomous. Gunilla is always ready to help you and to answer to your questions. Swedish people are very welcoming and friendly and all my co-workers was ready to help and to teach me.
I didn't went to school here in Sweden.
For the relation with the patient, i think that's a good idea to learn Swedish. Some of them speak very wel in English but it's normal that most of the time, everybody speaks in swedish. But you can also learn how understand a situation without understand a word ! It's great to know how read an expression on a face !