I like the scrolbars almost as they are.
They should not overlap with the buttons (at first I was thinking of it as a bug!) and they should be tick so that you can use the scrollbar to navigate faster to where you think you want to go and then refine the search with the kinetic scrolling.

Actually you can show it up and when using the kinetic scroll, make it disappear and reappear automatically when the scroll is finishing/has finished.
(a fade in/out effect would be great).

Asking too much?