No, you can't use any USB keyboard or mouse with the device. It's a hardware issue, not a software issue (the device has a client, rather than a host, connection). It's different for the 302 model, since it has a USB host connection, and it's _software_ that keeps you from being able to use an external keyboard or mouse on it

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I'm not sure about the 360+, but the Pro series devices (60x/90x) have recently got support for Bluetooth keyboards.
You seem to be going through pretty much the same experiences and getting the same ideas as many of us who got our devices earlier. I think if you search this forum's old posts, you'll get most of your questions answered instantly, as just about everything was brought up and hashed over soon after the devices first came out.