...i've used both and my experience with FB Reader is -like you- that one can only go page by page by "tapping" the top (pg bck) or bottom (pg fwd) of the screen (so no scrolling)... but with MGutenberg i've found i can go full page just by "tapping" the center of the touchscreen once...

...about the shortcuts, i've noticed that FB Reader usually opens the last opened book, but that's as far as can think of a "shortcut"... maybe other users have other ideas...