In a published webpage presentation, it would be nice to be able to scroll up and down using keyboard keys instead of the scroll bar.
I have a presentation that is a rather long page, and for several reasons we don't want to split it into separate slides (one reason being the inability to easily copy and paste text from it - see also idea: 'Option to disable "click to advance" presentation page").
This is critical for accessibility.
Additionally, the scroll bar should appear by default to at least indicate to the view that there's more content to scroll to. Otherwise, the viewer doesn't even necessarily realize they're missing some of the content. Currently, the vertical scroll bar only appears if you hover the cursor over the right edge of the presentation.
Ideally, there wouldn't be scrolling in the first place--or, at least, an option for the presentation designer to indicate whether the content should vertically expand or be constrained to scrolling within a frame.
In effect, a presentation published to a secure webpage needs to be thought of more like a webpage and less like a slide from a presentation.