Full-screen is definitely on the list for future features. It would have been in 1.0, but I couldn't find a way to do it without a lot of work, so I got lazy.

You can change the default zoom behaviour with the Zoom -> Automatic Zoom menu, but there's no keyboard shortcut. I'll consider adding that, too.

I see no need for a browser mode when the OS already does thumbnailing for me, and I don't use metadata to categorize my images, I use a directory structure, for which the Move Image/Copy Image features are enough... I figure that if you want that, you're better off using a dedicated program.