setVelocity not 'working' is due to the different
simulations (found in the config, like simulation="tank"
or different classes as there are a few object types that can't be setvelocitied..
Usually they are static objects, houses etc...
Some objects can be setVelocitied after they have been 'pushed' first by creating a bullet and hitting the object with that bullet and then using setVelocity...
Also, if you setVelocity an object that has no geometry it will move pretty weirdly, usually doing the opposite you setVelocity it to do..
And yeah, I'm wondering that mine bit as well..
Mines are very peculiar thing as they don't really exist in any level...
But that's too off-topic