the equatorial inclination is an inclined plane on the earth..

The equatorial plane is the flat surface perpendicular to the axis of the earth through the largest part - i.e. the equator. Since the axis tilts at 23+ degrees, so does the plane.

A satellite in an equatorial orbit flies along the plane of the Earth's equator. If an orbit does not lie at an equatorial orbit, then it will not remain at a fixed state.

No, it does not. The inclination of the moon's orbital plane is anywhere from 18.3 degrees to 28.6 degrees. The moon does intersect earth's equatorial plane twice during every sidereal orbit.