If you don't want websites tracking you, and you don't want the pages you view to be saved in browse or search history, you need to active the incognito mode and this is what you need to do.
If you don't have installed program for editing PDF documents on your computer, then you can use web application PDFescape which allows you to edit your documents in your browser.
Mac OS X 10.8 Mountain Lion is out and ready for download. If you are willing to invest $20 and an hour of your time to upgrade you Mac computer, you won't be sorry.