While two-finger scrolling in Preview is nice, it is not very comfortable when slowly reading very long PDFs.
What I've figured out to this point is that I can use space and ⇧+space to move forward and back a page at a time; and ↓ and ↑ arrows to move a couple pixels down.
Is there any way I can set the arrows to move down a line at a time? (Note that with zoomed in document for reading, it takes 3-4 key presses to move down a line)
Or, any way I can set space to move down only half a page?
Maybe there are some other tips for comfortably reading/scrolling long documents?