Could someone please help me ask around for the answers to these questions?

1. Is it possible to go on exchange to Germany for the last year of high school and enter university in Germany straight after?
2. Where, how and could an international student work whilst studying in Germany?
3. What is the requirements to enter a German university to study an education/teaching and an arts degree?
4. What could be some laws, rules and/or etiquette easily breached by Australians? That is, things not allowed in Germany but is in Australia.

Please help me! Thank you for your time!