You should make a backup! And You can use AdblockPlus, HTTPS Everywhere, LastPass, Zenmate for Chrome with your Chrome browser.
and maybe you can use HitmanPro and CCleaner
Thanks for sharing your config
Looks plain and simple "which is good for a shared PC" Agree with using/making back ups of the system. If in a family environment, may consider making guest accounts for everyone else, while you run the admin one.
In Windows 7 you can create a System Recovery disc and a System Image from the Control Panel. It's simple yet effect, if your OS doesn't want to boot, or you haven't your installation disc on-hand.