I think the WT, if actually called to account on this, will claim that the words "mentally diseased" were used in a metaphorical way in the article, which is just about true.
We often in conversation here use the word "cancer" or "cancerous" in a similar way. Of course Paul is using the word in Gk. which could be translated "sick" as in the margin of KJV, in a metaphorical way, what he is sayingis that the peson has an unhealthy interest in disputes and debates etc.
Freddie Franz's "mentally diseased" is simply in error as tranlation, it does not convey the writers thought, but it suits the WT's purpose, as does the use of the phrase in the article, your average Dub will apply it literally.
This is not to say that what you are doing Amelia, is a waste of time, far from it, I am just looking at ways the WT will wriggle. The point is that if publicity can be gained ,that is a good thing. Our local paper had a story on someone objecting to the sale of toys we used to call "Golly Wogs", saying the toys were racist.
Of course, this person was shown to be in error, but it got discussion going for a good while on what exactly was, and was not, racism.
Your excellent idea is going to put the spot-light on JW's weird and hatefull attitudes, very well done !
I would be careful to not overload the police with info, just stick to the pertinent points, and offer to give them any extra info they may need, do not come over as someone who wants to get back at the W.T, just express that you are mortally offended by this hate crime.