Personal attacks are a red card in hockey and soccer (and a pig splat in Village Square). You're gone.
Build, don't destroy.
Respect what's there before you. When you edit someone's work, think build instead of destroy. Sometimes you have to remove things to build them, but keep the goal firmly in mind. Destroy-each-other fights will end in both parties being outta here.
Op-Eds are sacred.
You could technically edit an op-ed, but don't. Don't ever. An op-ed is a copyrighted work. Feel free to use the comment thread.