And would it change Earth's orbit?

It would depend on what the scriptwriter wanted.

And would it change Earth's orbit?

 

Nope

 

What would happen if the Earth's rotation was highly increased?

 

Nothing. When you are in a car you don't really notice how fast you are going. Same goes for the planet. However a sudden increase/decrease in the earth's rotation would probably kill a lot of humanity. Like if the car was in a car crash.

 

If it were exceptionally large we would have shorter or non-existent night which could affect animals and the planets natural magnetic field. Ridiculously large rotation might blow the atmosphere off.

Edited August 13, 201510 yr by fiveworlds

It would tend to flatten more at the poles. Tides would likely increase (depending on natural frequencies) or at least change. Volcanic activity and Earthquakes would likely increase.

The climate would be more even throughout the Earth.

We'd get even better benefits launching rockets from near the equator than the poles.

Shorter days and nights.

The days would be shorter.