Hi Scott
You can re-install Zone, but make sure you have no other programs running, and manually set up a restore point. (Also create a restore point before you manually update any software)
No Security suite is perfect but the top names, Norton, Fsecure, Zone, AVG, even MacAfee are all pretty good, so just go for the one that you can get the best deal on.
Make sure you un-install any other security software before installing another one.
Hope this helps

Bill