planet - Would Venus have any significant effects on Earth if its orbit were entirely within the habitable zone?

Changes on Earth:

Except for possible tides and possible eclipses, if it were near enough, no.

Changes on Earth's orbit:

Venus would establish some resonance with Earth's orbit, if it were near enough or in one of the exact possible spots. This will not have a major impact except on year's lenght and Sun illumination on Earth.