I have (had) nervous tics with my hands, everything from flapping (I apparently did this a lot until about 4 years ago, during my freshman year of high school) to wringing them to shaking them (axis point seems to be my index finger) to typing what I hear people say (or just words that feel cool to my fingers; I still do this a lot) to wiggling my fingers. I do have complete control over these, but then I get this weird sensation in my hands when I stop. It's not painful, just weird, like really tiny and mild but widespread tingles. It's the same sensation I get when I try to stop my legs from shaking due to restless leg syndrome. They're probably related in my case.

I'm not sure what you mean by flicking, but I have personal experience with hand tics.

As for your meningitis question, I googled it just now and everything seems to be saying there's not, but it's an interesting hypothesis. There is a lot saying that autistic children tend to have more immune system abnormalities than normal children, though it tends to manifest itself in more ear- and upper-respiratory infections. But I wouldn't rule out meningitis. So now we have a new question to answer: if there IS a correlation or cause-and-effect relationship between meningitis and autism, which causes which? Does autism cause kids to have a higher likelihood of contracting meningitis? Or does having meningitis as a kid cause developmental damage that could potentially lead to autism?