1) bookmarks, notes, and highlights sorted sepatately: redundant (there is filter by category) and disrupts the logical flow of information - to keep it linear, you have to use only one category of marks; 2) cumbersome large text selection: drag to scroll is slow and you often loose the selection, it is impossible to go past a picture, and there is no "drag selection up/down & continue expanding it" feature which would solve this problem and which is present e.g. in web browser or email apps