Could you tell me what occulsal X-ray is? And can occulsal X-ray take good picuture of upper palate to detect any fracture at #1? At midline?

Limited utility. For dental issues a come beam or cbct will give a lot more information regarding both your issues.
Direction of Bite . An occusal radiograph or "x-ray" is one that is taken in the direction of the biting surface of your teeth. It can be done on the upper or lower jaw. It may be helpful in determining a fracture at the midline. A cone beam ct will be much more accurate in this case.
Occlusal is: The biting surface. Thus xray puts the film, or sensor on the biting surface instead of the inner surface of the teeth. The xray tube shoots through the teeth and bone from the top on the upper jaw and from below on the lower jaw. If your #1 is an upper front tooth then yes it would work well to do what you described.
Occlusal xray. What caused the consideration of this film? A "fracture at #1" is a most unlikely.Tooth extraction, maybe, but if trauma like assault, mva, etc, an isolated fracture at #1 would still be a very unlikely result. The occlusal xray has little value- "way back" in your mouth, it's highly unlikely the area could even be captured . No ct is necessary unless a compelling reason exists.
View from the top. Occlusal x-ray is the x-ray taken from the top of the subject being radiograph, as in this case, the top or occlusal surface of the tooth. An xray can only detect fracture if the fracture line is at an angle to the xray beam. It will not properly diagnose fracture. In fact, high resolution cone beam is a better radiographic diagnosis. Trans illumination is also good to diagnose fracture.