1) Things that students should understand about being good digital citizens is not only pandering or contributing towards inappropriate web content (although that is one), they need to explore the web, taking advantage of the good there is out there, as well as contribute to the resource, create web-powered ideas that will foster web projects all over the world. They need to take the web to a new level and make people see it as a tool they haven't before.
2) Atomic Learning's Creative Commons workshop on licensing creative work will be helpful when encouraging students to create web work
3) I think a good way to teach digital citizenship is to compare how students learned 20 years ago and the capability of learning now with all the web tools available. I think it makes the current situation look very exciting.
4) I think parents will get involved by watching their children becoming engaged in their web projects. Through the projects the parents will see the true capabilities of the web and encourage this path of thinking.