You probably need to do some study on how Microsoft expect Windows 8 to be used, especially if you don't have a touch screen.
Two thoughts
1. If you don't have a touch screen, Adobe Reader Touch may not be the best choice. It is much more limited than the regular Adobe Reader. Did you pick it for a reason, or just because Microsoft encouraged you into their App Store?
2. Try a right click, sometimes seems to substitute for a touch off the edge. I know you can't just use the mouse as if it were touch.
