Thought I'd pop it into an answer for clarity - and more words:
Your picture answers these well. Look at those blue lines. These are light rays from the point at the top of the Object.
At the real image point, they are all together, in another nice sharp point. This is in focus.
Point 4 needs some clarification - the diagram is a construct to demonstrate how light rays are affected by the lens. At the screen they are spread apart - with light rays from that point appearing anywhere between the blue lines, and light from all other parts of the object doing the same. So the image of the top of the object now becomes a smear across the screen.
Oh, and at point F - it will be a small blur on the screen. It doesn't vanish.