One: the cavity is a design element, not leftover space. It carries services, it provides the acoustic separation, and it must be sized for both. Two: service separation is a principle, not a slogan — cables run in their own layer so that neither the acoustic nor the electrical performance depends on the other.
Three: sealing decides the result. Joints, heads, bases and penetrations are where a rated wall loses its rating. Four: bracing is structural. Cross rails and through-holes tie the studs into a grid, which is what allows tall walls and heavy openings without secondary structure. Five: openings are designed, not cut. A reinforcement module at every door and every heavy fixing point.
Six: reversibility is a cost decision. A wall that can be opened and rebuilt is cheaper over the life of a building than one that must be demolished. Seven: flatness comes from the frame. A controlled plane lets the finish be thin, the tile be large and the paint be invisible.
Eight: fire, smoke and thermal properties are three different things, and the rating belongs to the assembly. Nine: the interfaces are the risk — the head, the base, the flanking path, the door, the services. Those are the lines that should be drawn on the partition elevation before the wall is ordered, because they are the lines that decide whether the wall performs.