Swing weight is Rotational Inertia, it has no vector. Adding mass anywhere away from the sellected pivot point increases SW. There's no "counter weighting" SW, it can only increase.
SW is used to compare two racquets restlistance to rotation. Therefore the point of rotation does not matter as long as you use a consustant point.
All characteristics of a racquet have benefits and negatives. IE: weight is obvious.
The body is multi jointed, the motion is compound movement there is no point of rotation, there are many. The further a point point is from the racquet the faster it's linear velocity for constant rotation velocity.
Others probably disagree but you don't use a lot of wrist in tennis ground shot. Most wrist action occurs after contact and thus has little impact. Torso rotation is greater in both rotation and affect, hence the move away from closed stance to open stance ground shots.
Simply higher SW will typically resist the impact of the ball but also resist players acceleration.
Static balance assists in knowing centre of mass, but SW give addition info of polarity. TW, SW, W, all nice to know but RA and frame shape Ixx, Iyy also affect play. Most people have an idea what feels right so can eliminate most racquets when selecting. Though you can always increase SW, TW and mass through adding mass. So going under your desired feel is beneficial as you can increase but can't easily remove mass easily.
There's no perfect numbers. Pros demonstrate this by the enormous variance in racquet and strings.
