Regarding the engine. You are running a 2-cycle engine, where the oil is mixed in the
fuel. No matter what the fuel mixture setting is, you will get oil spray out of the
exhaust. If it bothers you to get oil on the landing skid, then get an exhaust
diverter to point the exhaust away from the heli. However, when you are hovering,
you will of necessity be lingering in your own exhaust cloud, which will get oil
on your heli.