Is it splashing without clothes in it? This is likely normal as these machines have a very aggressive agitation. The clutch has no function during agitation and if you can't easily rotate the basket by hand, then the brakes are fine. There is nothing in the transmission that could cause it to agitate faster than normal. As far as the motor overheating, you may have a faulty motor switch. The switch normally opens to remove power from the start winding once the motor is running. If the switch is stuck the motor will overheat and it's internal thermal overload will trip shutting the motor off until it cools. There is also the possibility that the timer is trying to select more than one speed at a time which will also cause the motor to overheat.

Eric