if he has dark circles under his eyes, that is usually the sign of an allergy, very often a milk allergy. Usually whatever he craves and has to have nearly every day is what he is going to be allergic to.
He sounds hyperactive. There is a diet for that that works well, by taking him off sugar, and all artificial flavorings and colorings. If he will eat yogurt, that will help (you both) with the candida, but the yogurt should be plain and then sweetened with stevia and vanilla or one of the flavored stevias. The yogurt with Sugar added will be counterproductive.
I would repeat the parasite cleanse, if it were my son. Sounds like some parasite activity.
If you took paxil during your pregnancy, that drug is filled with fluoride, so you want to give him a high calcium diet, or give him supplements. Now if he is allergic to milk, you are stuck with just supplements. I suggest a calcium-magnesium supplement (which is good for the charley horses kids get at that age) and a good probiotic for the candida. I use the acidophilus from Walmart, ant it works good for me. One sign of candida is smelly stools, so I think you are right on about the stools. Give him a couple of capsules every day until the smell goes away or he gets diarrhea, whichever comes first. Then at the first sign of the smelly stools again, repeat.
None of what you described sounds like Tourette's to me, but the truth is a good clean diet, done consistently, will provide a clean bloodstream, and will take care of many problems.
Regarding the pneumonia, a lot of our immune system begins with proper bacteria in the stomach, and the acidophilus will remedy that. We take things into our chests when we are in situations we have no control, so let him participate in his own healing as much as possible.
I would try these simple things. Miracles can happen from simple changes. Just for encouragement, most hyperactive children are super bright, even geniuses. Think of how he can be creative and not put into a box. Please post results.