I have format-all-buffer, and currently I'm calling it in normal mode with the ~ key...
But I figured I would love to call it always when doing :w to write the file as well... is there a way to do both things?
If I understand correctly, you want to call the command format-all-buffer every time you save a file.
You can use hooks for that, add this to your config:
(add-hook 'before-save-hook 'format-all-buffer)
P.S. You can type that in the buffer named *scratch* and use C-M-x or eval-buffer to evaluate this piece of code.