1. disable Fullscreen "XY is now Fullscreen" text. Set full-screen-api.warning.timeout to 0 2. disable Alt key: set ui.key.menuAccessKeyFocuses to false 3. don't select space after double clicking a word (together with auto highlight selection addon very nice for skimming code in browser like GH): set layout.word_select.eat_space_to_next_word to false 4. reduce forced wait when downloading a file (Download button in small FF-modal takes time to enable/activate, hard to explain, but annoying) : set security.dialog_enable_delay to 300ms 5. disable "This Connection is not Secure" Warning in (for pages like fritz.box together with XCkeepass very annoying) security.insecure_field_warning.contextual.enabled