When the fuselage parts are glued together the undercarriage wire is trapped between the motor fuselage doublers and then sanded. The offset on the rudder is designed to make the model fly away from the pole to keep the flying lines tensioned. The models are designed to fly anti-clockwise around the pole.
The slot for the motor should be a snug fit, (otherwise the motor will fall out) but not too tight that you risk splitting the fuselage when inserting the motor. Elastic bands are commonly used to secure the motor in place. The tether hook for securing the flying lines to the model is inserted through the fuselage at the point indicated on the plan. A straightened out paper clip is good for this as it allows easy adjustment of the plane’s flying characteristics.
Finishing is simply a case of painting the model to your own personal design, you do not have to completely cover the plane, a few stripes can make your plane stand out.