You can do almost anything with a GridBagLayout, but it's not easy to write, and even harder to read! The simplest approach is just to use JPanels within JPanels to build it up starting from the smallest groups.
At the topmost level a JTabbedPane will give you the tabs and the means to navigate/control them.
In real life I would expect to have to do some experimenting to get the right results and sensible code, but as a starting point...
1: Yes, I'd have a JPanel for that whole "File" area
2: How about a JSeparator(javax.swing.SwingConstants.VERTICAL)
3: I would make that a JButton, if only because it's a thing you click.