I'll look at the arrow issue in Nightfall... you're right it is scrolling 1px at a time. Almost positive I can increase it to something like 1 row at a time (the small row size since they vary in height).
As far as the amount by which clicking the scrollbar background jumps the slider, pretty sure that isn't something we can tweak, but I'll look into it.
Workaround: Select a member then use your keyboard arrow up/down to scroll 1 member at a time
