you can rename the camera in the camera node at least. It dose look like the cameras are only at the top in the preview window on the left, but cant be reordered in the select camera button.
In the "select different camera or viewpoint" button, I agree cameras should be movable in the list, they should also have color options so you can select them by color rather then trying to remember what name is what camera. The camera icon in the 3d viewers should also take a color so that its quick to locate and select visually.
There remains a lot that PS could do on this front.