Hate to brake the news to you but all the things you mention as anti-social behavior are just kind of cat things! Lots of cats will only drink fresh water from the tap. Headless mice is their way of presenting you with a gift. Would you really expect the cat to pick dirty laundry to sleep on if clean is available? Wiping his feet and pushing on the cat door...so you will pay attention to him!? If he is sick, he can't stop to access the difficulty involved in cleaning the carpet. That wouldn't be cat-like at all!

The kitty obviously has a physical problem that will need to be addressed by someone with more knowledge than I. Just wanted to state that, while the "anti-social behavior" may be a change for him, it is all quite typical cat behavior (other than the vomiting, which he certainly can't help) and he has just been very well behaved prior to this! Perhaps as he started feeling ill, he started trying harder to gain attention.

The vomitting of undigested food, increase in thirst, and attention-seeking behaviour suggest Phos or Ars.
Phos animals tend to be very warm between their "shoulder blades". A causation for Phos is exposure to drenching rains. Did he get soaked to the skin recently? How is he with thunder storms? With his new behaviour, is he more affectionate too?

A need for Ars would suggest that he has eaten some poison. An Ars animal is very restless, sometimes demanding and very anxious.

If you can think what happenned in his life just prior to these symptoms it can help to decide on a remedy.

neutered cats cant eat food containing potash, (kailium)they develop kidneystones, and other problems, and the mucus vomiting, is a worm sign, he needs devorming, and give him one dose kailum carb 200.

Nooooooooooooo
Crush a tablet of KaliCarb 200 in his water bowl and let it dissolve before he drinks it.
Simple.

As for wormers, I think the conventional ones are pretty effective and not bad for them - just some herb concentrates I think.

OK, you can crush it and put it on his food instead.

Hi
Just crush the tablets between two clean spoons.
Grab hold of his head and slide (push, shove) the spoon into the side of his mouth.
This works.

Funny thing is, truly healthy cats do not drink water on any regular basis. Only on occasion.