a) removing the black bars to the side of the image (when viewed in Shotcut)
b) scrolling from top of the page to the bottom
tried messing around with the Size, Position & Rotate with the ‘slow move up’ preset, which for some reason actually moves down, but can’t get issues a) and b) corrected. Here is a image example
It is not possible to make a full-fledged scroll, having such an image as in your example. If the video format is 16x9 (1920x1080), the picture with notes should be 9x16 or even longer vertically. Usually, for such videos, pictures are prepared in advance, gluing several pages of notes under each other. Prepare the desired image in advance in any photo editor, for example I use KRITA.