1. Your Spirit is you now and when you die. When you die you shed the physical body as it were but your Spirit retains all consciousness. The physical body is a mode of transport for this level of experience. Think of it as a car. When you're finished with it you move on and get something else.
2. Because it is you it has whatever consciousness you have, even more.
3. It wouldn't make sense to you right now, the point of being as you say a disembodied Spirit. You are actually Spirit having a physical experience and once you fulfilled that experience there isn't need of the physical body.
www.mindsoulsspirit.com.su
4. The above reasons are exactly why we do reincarnate. We often can't get it all in one lifetime so we come back do it again till we believe we got it all together.
5. We choose to come and experience and we then take that back with us to the one. In effect we grow back into one from whatever we choose to experience or in other words we lose our way in our experiences and find our way back to the Spirit.