With Bluetooth enabled, go to System Preferences > Bluetooth > Advanced > and now make sure the top two checkboxes are empty: "Open Bluetooth Setup Assistant at startup if no keyboard is detected" and the one for mouse/trackpad.
To get full brightness back, I use the AppleIntelIntegratedFramebuffer.kext from Snow Leopard (10.6.8). (No 64 bit support, so still booting with arch=i386.)