Your flash drive looks okay (probably should have linked you to the
USB Devices Compatibility List) and I know from personal experience that Path of Radiance works. I've never heard of Dios Mios Lizard, but if you plan on doing any converting I'd recommend using Gamecube ISO Tool as it's quite versatile and somewhat noob-friendly. Also, what IOS are you loading into when you run USB Loader GX? Since it's seeing your games you probably have your drive plugged into the right port (top one I believe, should be port 0 in the loader), but I want to make sure. cIOS 222 (normally hermes) and cIOS 249 (normally d2x) can behave differently, especially with regard to the port you have your drive plugged into. I'd recommend 222 for most things and 249 when 222 doesn't work.