The last one was closed because you made a suggestion + name and shamed at the CS forums. Former which isn’t processed by CS and latter which is against the forum rules which you were informed.
As advised by Felranys you have to use the ingame report options.
You could discuss with the police, but before that, you should discuss with consumer organisations specialised for these problems. What you experience could be considered “stalking” and a form of harassment, however as the offender is not really trying to figure out where you live to stalk you IRL I meant or make actual threats the chances that police may intervene near non-zero. I have seen such cases prior on the forums.
But it does. It just doesn’t generate a lightning bolt hit on him the moment you report them.
If you made it under the ongoing harassment category it will continue to be on their radar. You will have to keep an activity notepad about what happens and where/what character and so on though. It will be tiring.
They won’t do this. Even before the stalking it is more or less abused by goldsellers/boosters for illegal farming and I don’t see them removing it even with that reason in mind even.
You can suggest that through the ingame feedback box. It is a good idea.
This is unrealistic, certain ISP’s uses a dynamic assigned IP that switches (regularly) or on request or even worse, he may be sitting in an internet cafe or campus and you would hit an entire row of innocent people.