User Control screwed up but unable to click on icons with Mouse on OSX 10.8
I'm not sure about the answer, but my suggestions are too long for a comment. So I will create an answer nontheless.

First: Installing updates with the keyboard should be easy if you are able to launch the app store. When you are in the appstore, use your "tab"-key to go through the main menu. Hit "space" to enter the selected item. Hitting the tab key again will bring you to the other items in the window (like the "update"-button). 

If updating does not solve your issue and you are sure that there is no Magic Mouse somewhere in your bag or whatever, which is accidently turned on and can cause issues, you could try to reset NVRAM. This article should be interesting to you: https://discussions.apple.com/thread/4061591?start=0&amp;tstart=0