Good q specialagent, I think the key here is that everyone with Tourette's is so completely different!
Motor tics vary drastically, I can only give you personal experience of my DS.
He doesn't touch anyone, but when he is over-stimulated, excited or stressed (so watching a new, exciting film is actually a v good example), he will involuntarily fling his arms and legs out and jump to his feet, accompanied by snorts and grunts and head jerks.
He has the mental capacity of a 6yo and would apologise if he had accidentally hit someone whilst his tics were active, and I will briefly explain the situation and naturally check the person was ok.
Thankfully that particular situation hasn't arisen yet but I'm fully prepared for when it does.
I've also tried v hard to prepare my DS that inevitably some people will not understand, and will judge, point and stare, but I'd hope that the majority of people would understand.
I also pre-empt situations by pre warning people that my DS is likely to start to tic if he is stressed or emotionally aroused, the majority of people are curious but accepting, and so far I feel we've been very lucky in that respect. 