Prior to the introduction of iOS7, it was possible to simply plug an iPad into any computer and reset it. iOS7 changed all that, for the better.
So long as you are running iOS7, setting a password will require your AppleID to reset the device.
You can also turn off "Simple Passcode" in Settings/General/Simple Passcode, after which you can set an alphanumeric password of any length.
In Settings/iCloud, you can turn on "Find My iPad" and track it with another iPad/iPhone/Mac, so long as it has internet access.
You may not ever get your iPad back, but you can ensure it is useless to anyone else.