No - that couldn't work. I've looked at the code and committed a working version in which init() is called. I've also added the plugin to powertac-server. If you update both projects you'll see your log messages.
The visualizer is, at least for now, only part of the server. That's why it can't run separately, but it should be built in a way that it could later on. VisualizationProxy is a component internal to the server and will not be available when running the visualizer as a separate instance. In the latter case you'll have to receive all messages though a JMS channel, but that is not important for now.
All you need to do now is just run powertac-server. There is no need to run both projects.