I don't even want my browser to support searching from the browser UI. If I want to send information to Google I'll visit their web page directly. I don't want to do it by a misclick.
It's surprisingly difficult to disable searching from the browser UI in Firefox. Firefox insists you have at least one search engine enabled at all times. The best option I know of is to set the undocumented setting "browser.urlbar.update2.engineAliasRefresh" to "true" in about:config, which enables an "Add" button in the Search preferences for adding custom search engines. You can then add a fake search engine on localhost that will always fail, and set this to be the only enabled search engine.
It's surprisingly difficult to disable searching from the browser UI in Firefox. Firefox insists you have at least one search engine enabled at all times. The best option I know of is to set the undocumented setting "browser.urlbar.update2.engineAliasRefresh" to "true" in about:config, which enables an "Add" button in the Search preferences for adding custom search engines. You can then add a fake search engine on localhost that will always fail, and set this to be the only enabled search engine.