I must say arwoo you certainly impressed me with this post. Keep going like this! Now let's hope you'll find a solution for the botters.
I suggest to use the anti-hack that was used back in EMS, this was a way more intrusive anti-hack which was able to make it so we practically didn't see any hackers in EMS.
The problem is, what number does 8k accounts mean? It's basically 0 if all those 8k banned hackers just instantly create new characters on new accounts. There needs to be more action taken from a different point of view. As you're banning 8k+ accounts weekly those 8k+ accounts are hacker generated each week and there, somehow, has to be thought of a solution to stop them from recreating their accounts.