The effect of rotational velocity is usually calculated with centrifugal/centripetal force.

[tex]a = \frac{v^2}{r}[/tex]

[tex]F = ma = \frac{mv^2}{r}[/tex]

where v is the velocity of the object, or in the case of rotation, the rotational velocity at the surface of the object.

which you can subtract from the standard gravity calculation,

[tex]F = G\frac{m_1 m_2}{r}[/tex]

and

[tex]a = G\frac{m_{(body)}}{r}[/tex]

So, you would get:

[tex]F = G\frac{m_{body} m_{object}}{r} - \frac{m_{object}v^2}{r} = G m_{object}(\frac{m_{body}-v^2}{r})[/tex]

and

[tex]a = G\frac{m_{body}-v^2}{r}[/tex]

Of course, the higher the rotational velocity, the lower the overall pull of gravity for objects at the surface.

As far as rotational velocity affecting the pull between two celestial bodies, I'm not sure. Does an object spinning in a vacuum experience less weight?

If you are doing rotational frequency, are seconds appropriate? The earth rotates once every 24 hours. The sun poles and equator (and core?) spin at different rates, but say once every 3 weeks or so. Of course, one can always convert units.