Sweet!
I always have to turn object preview to bounding box or hide before render. I often forget to turn off edit object population as well. I rarely use RTP as I forget and try to switch to a shader before it is done tracing and whoops, freeze time. I, of course do not understand the things about rendering that you do,...but it does help my unit to do that. I have Poseray running all the time as well as email, so that could be part of my problems too. I do not know if Poseray goes dormant like if it is just hanging in the background or not.