A few programs cannot be captured at the moment, however many can, and technology will be added in the future for capturing those other programs as well.
Each window's contents updated in real time and you can adjust the target frame rate of each window as desired to allocate more resources to the programs you consider important. For example, a video can be captured at 70 FPS while at the same time notepad can be captured at 20 FPS. Performance is heavily optimized to minimize judder, so you should expect things to run as well as they would on a typical monitor. This should run on Windows 7 about as well as it does on Windows 8.1 or 10.
Once you arrange your windows how you like, if you exit out of Multiscreens and then open it up again your windows will stay where they were. You can move windows around in space and change their size, and simply select a window that you are looking at and your focus will change to that. No Headless Ghosts are required, this program works fine when you simply have a single physical monitor (or headless ghost) plugged in.
You can turn a webcam on if desired and its contents will be displayed below you, this is one simple way of seeing your keyboard in VR.
There is a "virtual taskbar" that allows you to bring up programs by clicking on their icons below.
Enjoy, and let me know what you think! I'm happy to listen to feedback and will try and make this the best product for all of you as possible :)