I do a lot of CAD production, spreadsheets, etc. - I'm not saying touch can't be useful in such a situation, but given the current office paradigm of sitting at a horizontal desk with vertical monitors, it's a non-starter. Given the glacial pace at which most office environments upgrade (how many still run Windows XP?) I'm not expecting that revolution to come around anytime soon.
By gaming I don't necessarily mean 'FPS'ing, but still things where you sometimes need quick and precise reactions. I used to find it impossible; now it's no sweat. I guess it's just an adaptation of having acclimated to it over 7 years. So far the worst I've gotten are sore fingertips. I suppose that beats CTS. As for the angle, it's on the MBP so it's no worse than typing. My only gripe is the "sharp" edge of the laptop - which seems to be something of a common complaint.
I have my monitors on swiveling arms, while they are not touchscreens I sometimes envision how cool it would be to work with them closer to me, angled just right. I would think something like CAD might work very well in this fashion. I know what you mean about the vertical monitor and yeah I wouldn't use a touchscreen that way either, but right under me using a finger in one hand and a stylus in the other would be nice. Of course now we are delving off track quite a bit talking about large touchscreens on swiveling arms, ahh one can dream can't they.
But a bit of a paradigm change might yield cool results. I keep my SP3 on a dock between my 2 monitors, right next to my non mouse hand. So I can reach over just a little bit and use the touchscreen to check email, scroll, open files, etc on the main screen, in essence the SP3 functions as a trackpad, it's pretty cool.