Assigning global keyboard shotcuts for cross-application behaviour? On PC: To open Chrome, the command was Win+3, a new window was Shift+Win+3.

It just occurred to me how much I relied on this. How can I have something as beautiful and simple as this on Mac? It should try to open the most recently active window, but should avoid changing Spaces as that is super disorienting. It shouldn't disorient.

Can I write a custom macro? Or program? Or command? Or ANYTHING to have this work on Mac?
macOS should get you up to speed a lot quicker.

See macOS Sierra: Create keyboard shortcuts for apps for creating custom keyboard short cuts:


  You can create keyboard shortcuts only for existing menu commands. You can’t create keyboard shortcuts for general purpose tasks, such as opening an app.
  
  
  Choose Apple menu > System Preferences, click Keyboard, then click Shortcuts.
  Select App Shortcuts on the left, click the Add button , click the Application pop-up menu, then choose a specific app or All Applications.
  If you want to set a shortcut for a menu command that appears in many apps, choose All Applications.
  In the Menu Title field, type the menu command for which you want to create a shortcut, exactly as the command appears in the app, including the > character (type ->), ellipses (type three periods without spaces or press Option-;), or other punctuation.
  Click in the Keyboard Shortcut field, press the key combination that you want to use as the keyboard shortcut, then click Add.