iTerm2 pin Visor (hotkey) window
Yes, as long as you have version 3.0.0 or later (or pre-release versions). If you go to the "Keys" tab in iTerm2's preferences, you should see the "Hotkey window hides when focus is lost" checkbox in the "Hotkey" section. Uncheck it.
In 3.1.beta.5, it's under "Profiles", and then click "Configure Hotkey Window for the "Visor" profile you want to pin.