No, you've misunderstood or perhaps I wasn't clear enough. The physical won't move because, by that time, it will be atonic (i.e. in sleep paralysis) regardless of whether you notice this condition of not. When you experience that shift in consciousness and you get vibrations or the rushing sounds, as they dwindle, perform the act of separation.

Move as though physically. Do NOT imagine it (that part is right). Even if you think you are moving physically, you are not. Once out and you look around you will realise that you will have moved incorporeally.

As for vision, believe that you can get it. Demand it! If it doesn't work there are some deepening/anchoring techniques such as keeping on the move and touching nearby objects. This will help you to reinforce your focus of awareness on that level as well as prolonging the experience which will give you plenty of time to explore.

I hope I was clear now and good luck! I hope you have more success!