So, question about riven

Uhm ... E > R > W > R = kill. So , a lot

Or if you don't wanna do it you can always qrwqrwqewqewqerwqrewqrewqerwqewq ... wqwrewq

Honestly? Not that much. It allows her to use her spells faster, but it doesn't inherently make her do more damage.

I'd say it halves the time it takes to do a rotation.

it can take practice, but she gains dps as well as the ability to chain skills to protect herself. She's a double edged sword and playing her incorrectly limits her performance well playing well and clear minded allows her to pull off things you wouldn't expect