To begin, I decided to see what else I could learn about VDMX. It turns out they have an excellent Vimeo channel that has all kinds of interesting tutorials (ex. syncing the clock to Ableton or connecting to processing via syphon). I was particularly interested in the tutorial on using a game controller in VDMX.
I have my own game controller that I can use with VDMX.

I also figured out how each button is listed in the program. I experimented with it and created a project that uses the joysticks to control the position of two objects. I also experimented with using live feeds in layers, and fed the VDMX display window back into a layer to make the infinity-mirror effect. Each button on the game pad can also control an effect.

However, I am still in need of a concept for my project. I have some new technical tools that could make for an interesting interactive performance, but I have no idea what to make it about.

Notes on how VDMX understands the game controller.

The templates menu has lots of interesting examples that you can learn a lot from. I started with the PS3 controller example.