It is rarely needed anymore anyway. More and more websites are moving to HTML5 and unless you watch a lot of embedded videos you will actually find most websites function just fine. I know this from using my iPad at home (Which ofcourse does not support flash). Which is my primary browsing device. I rarely use my PC to browse the internet now unless i want to do something technical at the same time. For instance i've been using it all week and only once i have actually needed to use my PC because a website needed flash for its primary function.
But that's just me. Take a look at the sites you visit and see how much flash they use. If they use alot, then obviously your better off keeping it. As long as you have a good anti-virus even if it does have security flaws chances are you will be fine anyway.