On 1: the toolbar should reflect the status of the selected file list (file pane - either ‘source’ or ‘target’) - but I have noticed it only switches when you click on another tab in the other pane, so I have to look at this small issue.
On 2: Order is not important. The button can be dropped on your toolbar, but you need to be in customize mode (Settings > Customize…) to do that.
UPDATE: I made an adaptation to make it work correctly in dual lister view. You need to download version 1.4 here Script to show "pinned folders" permanently (while scrolling down)