One of the things about JupyterLab is that it really emphasizes extending and customizing the environment. Think of it as a platform for web-based applications and a reference set of components. We've tried hard to make the underlying platform have good support for power users. We've paid a lot of attention to making a good keyboard shortcut system, for example. I think it makes a lot of sense for someone to write a plugin for the system that registers keyboard shortcuts for doing tab management, maybe in the vein of a tiling window manager. Also, it would take changing only a few lines of code to move the file browser from the left side panel to the main docking area - it's just a widget that is registered on the left side panel rather than the main area.

We also encourage people to theme the environment, and provide themes via plugins. I think theming things with a lot more minimal whitespace would be an interesting project for users like you.

Also, for a power user, I'd definitely suggest running it in the browser application mode, which gets rid of lots of the browser chrome.

Remember - it's an alpha-level project, we're still experimenting a lot, especially on the user experience and UI. JupyterLab was built to be easily extensible and customizable, and we encourage people to experiment with customizing the environment in a way that suits them. And we appreciate feedback as well! Thanks!