2x18AWG plus shield drain wire for the sensor and 2x12AWG shielded for the motor. The extra bare wire without insulation is referred to as a "drain" wire for the foil shield. This drain wire should be connected to the GND terminal on the back of the ASC1. Do not connect the other end out at the actuator. Just leave the other end disconnected out at the dish. Connecting both ends defeats some of the benefits from shielding from motor noise.
Remember to only connect/disconnect the DiSEqC switch with all devices power OFF or disconnected (not just in standby mode). DiSEqC switches are easily damaged by connecting and disconnecting devices through the powered switch.
No harm using several wires in the bundle for connection to ground. It is not necessary to drive a separate ground rod for the dish. Most important to ground the dish pole to the structure ground used for your utilities. You may have a dedicated ground rod for the dish, but be sure that it is bonded back to the structure ground. It is not recommended and not code to have multiple ground rods that are not bonded together. Unbonded multiple ground rods actually can create problems by creating a potential (basically power flowing between two ground rods and going places that it shouldn't be).