Only if it is suspended.

No, because the motor and cartridge share the same frame of reference, unlike a suspended deck. With a modern dc motor in a decoupled housing on a seperate pod there is no issue with acoustic coupling from the motor. The noise floor of the vinyl itself is all you can hear.

Think about what daryl has said. A turntable is a measurement device - do you really think the motor and the measurement point being able to move in relation to each other is a good idea? Have you ever heard a direct drive turntable? If so what did you notice about the sound? Also suspension itself while it is a form of isolation is also a form of coupling... surely better to remove these two issues and solve the problem much more effectively using external isolation?