Is there any functionality in Chrome, iTerm2, or a keyboard shortcut app that will let me open a new window (Chrome or iTerm2) in a global environment?
It should open a new window regardless of whether previous windows exist or not.
To make a single hotkey always create a new Chrome window, launch Automator. Tell it to create a new Service Have the service take no input. Assign a single action to the service: Run AppleScript (in the Utilities list of actions).
Here is the AppleScript:
Save the service with a name like "New Chrome Window". Then, in System Preferences assign an unused keyboard shortcut to the service. You can then create a new Chrome window no matter what application you are in.
To improve the service substantially, replace "Google Chrome" with "Safari". :-)
To create a new window in a different scriptable app, replace "Google Chrome" with the name of the app you want to create a new window.
There's a bug where shortcuts for Automator services don't always work until the services menu has been shown once from the menu bar. Automator services also have small delays and they don't work when the frontmost application doesn't have a menu bar or a services menu.