Page order affects navigation in an intuitive fashion. When viewing a comic laid out from left to right, navigating right moves to the next page. In a comic laid out right to left, navigating left moves to the next page.
Page order affects navigation even when pages are displayed singly.
Scrolling still works as expected until the edge of a page is reached, at which point a page turn occurs. In Fit to Window scaling mode the page turn is instant.
There are three methods for doing this.
At the bottom of the comic window there is a progress bar, click within it to move to some other point in the comic.
Hitting enter or selecting Jump to Page from the Go menu will bring up a dialog box where you can type a page number. Hitting enter will move to the chosen page.
This brings up a grid displaying all available pages in a session. Clicking on a thumbnail will move you directly to the previewed page and close the thumbnail view.