That must be hard to watch your daughter go through! (((hugs))) to you
My brother had TS when he was young, but he's mostly grown out of it now. I seem to recall he took some medication for it, which helped, but he decided that he didn't like the side effects (it affected his drumming). But this was a long time ago, medications may have improved since then....
Re the scab picking - don't know if this might help, but my DD pulls her hair (eyelashes and eyebrows) - trichotillomania. It is very distressing to see her do this, especially when I discovered she'd completely plucked her eyebrows. It seems to be worse when she's anxious, but sometimes just when she's bored or she does it absentmindedly while reading.
So far the only thing that seems to help is to make sure she _always_ has a fidgit toy in her hands. I've tried a few different things but the only one she likes is a kind of putty that she squishes and pulls on. Probably it's an individual thing and something different may work for each person.
Therapy putty:
http://www.therapyshoppe.com/category/6-therapy-puttyIf you look at fidget toys, they also have some neat ones on this site.
She also likes Poster putty (which is way cheaper!) and you can get from any office supply store...
