Will yidio cause problems if you link it with your Netflix account?

No, there is no way to cause problems with your Netflix account.

Connecting your Yidio account to your Netflix account simply unlocks premium features on Yidio such as the ability to access your Netflix Instant queue, receiving personalized recommendations, ability to add DVD's to your Netflix DVD queue, etc.

Netflix does not share information with distribution partners such as Yidio nor does it give partners access to your account in any way.