After my last post, and a few more days of free-floating annoyance, I took the plunge and uninstalled EndPoint. Instead I put on AVG Free. Everything about AVG Free feels faster and less intrusive than EndPoint, and it did find all the same virii on the few infected files I had laying around. And when you turn off real-time virus protection, it freaking stays turned off!
And if you Symantec Endpoint Computer Performance, my blog entry is the top result. If you google Symantec Endpoint Performance the top result is Symantec FAQ answer about computers becoming slow after installing Endpoint.
Let it be known, that none of their suggestions would really help anyone not working in the managed corporate Endpoint environment.