You can go really big with the illusions but I would do that somewhere without people. Dad knows how to make them only visible to himself or certain others. But you might not want to take the risk.
Oh, shape-changing! You've gotta try that. You could basically look like yourself if you wanted. Not in the network, unless you want to upload the icons manually. But you can already do that right now anyway. Plus there are way more exciting things to shift into.