I would try changing their food. It's possible that the barfing is the result of a food allergy. I know some cats that can't stomach fish, and they will throw it up. Put them on a high-quality food like Blue Buffalo or Orijin. One that prevents hairballs wouldn't hurt to try either, in case he's bringing the food up with the hair.
If he is throwing up bile though, or you can see blood, take him to the vet right away, these are not good signs.
To help with the peeing you need to get rid of the urine scent everywhere they have previously peed. I would buy a whole new change pad, or soak the one you have in Nature's Miracle. If it has a cover on it, wash it with Nature's Miracle in the washer.
I have 4 cats, so I've been there, done that :P