Hi Mike ! Welcome to LD4all ! 
Great thing that another experienced lucid dreamer join there ! More we are, more we can share experience ! 
About vibrations and pain, it seems that there is not a lot of information about this topic. I just found :
[url]WILD pain?]
That’s strange, cause it’s something rather common, I think. A friend of mine often experiences vibrations, and they are sometimes painful.
Your invisible captor adventure is really weird. 
I saw you asked the same question in another thread, so I won’t ask you to make a special thread for it, tough it would have been worthy of making it. Too bad, cause in this thread, your question will probably stay unseen.
I’ll make a link to your other thread, in order to doing people answer in the same thread and not scatter replies.
[url]The Big OBE topic part II]
I never got the pulls, neither I felt anything like a rope attached to me.
About vibrations ( our main topic 
), Florence Ghibellini thinks it’s the dreamer energy when it is not used to create a rich and vivid dream. So we would have vibrations only when dreams are dark or void ( about dark dreams, have a look at “Pitch black” topic ). But what could perhaps contradict this theory is that the dreamer friend I told about above, had sometimes vivid dreams AND vibrations.