Stack Overflow hijacks my native keybindings for editing text areas. This is really annoying, as keybindings like C-h (for backspace) and C-b (for backwards character) are etched into my muscle memory due to chronic Emacs usage. How do I stop the site from hijacking these keybinds?
Instead of trying to change Stack Overflow's keybindings you could edit text areas with an editor. This way you can choose an editor with keybindings that you prefer.
Text areas can be integrated with an editor of your choice via plugins such as the Firefox plugin It's All Text. With such a plugin you can effectively switch from editing in a text area to editing the same text in an editor. An example on how to use that plugin is found in an answer to Emacs mode for Stack Overflow's markdown.