I hate bold text while coding. Is it possible to disable bold text (and underline) in every single file and emacs\'s interface?
If you are using Terminal.app, you can also go into your Preferences->Settings. For your current settings, go to the Text group and simply uncheck "Use bold fonts." Screenshot below:
The easiest way is probably
(set-face-bold-p 'bold nil)
Another possibility, which also deals with underlines, would be to evaluate the following snippet in a running Emacs session:
(mapc
(lambda (face)
(set-face-attribute face nil :weight 'normal :underline nil))
(face-list))