Writing mutual agreement between both parents

This needs to be done by an attorney so that it is enforceable.

Harassment

The best thing to do in this circumstance is to put it behind you. If they do report the relative then there will be a cause of action for...

Beach of contract

If the suit was filed after 4 years and was under CA law you should be able to assert that the SofL renders the suit meaningless.

You cannot register trademarks without using them in interstate commerce, so if you are intending to try to sit on them, you will not be successful.

If you are worried about purchasing these items, if they are from an entity licensed to carry these manga and otherwise obtained from a source that...

Is sending nudes illegal

If this is from a father concerned about his daughter, it is likely a scam.

If you have the email address, sending an email in general that addresses something of issue, may be legal depending on the content and depending...

If the site is illegal then you are liable for any illegal downloads as it is copyright infringement.

How do I go about clearing my name?

If you need title to the vehicle, you need to obtain it from your friend. Otherwise, his sale to you, was fraudulent if he misrepresented to you...

Whether or not you want to give it to her, if she files suit, you will be compelled to give it to her. So, I would give it to her since she signed...