Dave is pretty much right, and certainly good enough for a super sportster.

If you have 2 aileron servos, many radios "prefer" the 2nd aileron servo go in channel 6, which is usually flaps, giveing you flaperons. (with the mix setup on your radio). But that doesn't really matter here. Other radios can or do use channel 5 for that.

You plug the switch in to any slot on the RX. Obviously the battery plugs in to the switch and the switch in to the RX.

The reason the RX says 9/batt is that if you want to use the 9th channel, then you use a Y harness to plug both the battery(switch) and a servo in to the 9th plug. You can also do this on other channels, it doesn't matter where the battery plugs in.

DSC stands for direct servo control. It allows you to hook your TX to the RX using a wire, so you an wiggle your servos with out transmitting. It's useful at the field when things are busy and you want to adjust something with out shotting someone down. Though honestly, you don't see it used much.

Obviously, a plug on the RX isn't very useful by itself, so typically, you'd route an extension from the RX's DSC port to the side of the airplane to allow the TX to plug in.

You can also route the charge lead from the switch to the side of the plane so you can check your battery state or even charge the plane with out taking the wing off.