Is there a direct shortcut for maximizing/minimizing/restoring current window in Windows (10)?
I know I can press Alt+Space and then use the arrows to navigate and select, but I looking for a direct shortcut.
Windows – Direct shortcut for Windows Maximize/Minimize/Restore window
keyboard shortcutsproductivityshortcutswindowswindows 10
Related Solutions
Ctrl+W / Ctrl+F4 to close the current tab.
Alt+F4 to close the current window.
I’m not sure what you mean by “focus a specific window”. 
(Win)+n may be what you want; it will go to the nth task on the taskbar. If you want a certain combination (e.g., +5) to always go to a certain program, you should pin it to the taskbar. (If the task has multiple windows, hold while you press n repeatedly, and it will cycle through the windows.)
Another answer is to invoke Windows Task Manager (e.g., by Ctrl+Shift+Esc), go to the “Applications” tab (if you aren’t there already), select the task you want to go to (click or cursor down or type the first letter of its name), and press Enter or click on “Switch To” or double-click on the task name.
Best Answer
From Help Docs on Keyboard shortcuts in Windows: