Darksin :
Nah you should be fine, The only difference is a small downclock on clockspeed & no iGPU if i'm correct. Those games should play smooth as hell aslong as you have a solid GPU along with it!
Thats not my experience, xeon processors have a built in anti error functions which is the maine reason for xeons. Once he will play things like planetside it depends on what the load is at the same time while he is hosting, he has an increased chance of that part failing.
It depends on what the person is doing as said before, not much info is given, i would certainely not risk it, had some bad experiences with it.