Multi-Camera editing - switching cameras

There's actually an entire multi-camera view. You can add buttons to your Program monitor to access these or get to the view with Shift+0. If you click the Plus icon at the bottom-right of your Program monitor you can add the record button and the one directly to the right of it to toggle into MC view.

To toggle cameras with a shortcut you can hit the number keys, 1-9, and to cut to the cameras while playing back you can add the Ctrl modifier to those number keys. You can go into the Keyboard Shortcuts panel and see what multi-cam shortcuts already exist and add your own to commands that don't have shortcuts already assigned to them.