I'm sorry, I don't know what you mean by "new setting". As far as I know nothing has changed in Firefox for Android recently in relation to the settings of the search engine.
There is information here on how to set your default search engine within F...
Sorry, there's no way currently to remove that button. It will be automatically hidden once you visit a page, and will only show up when you are searching.It is designed to give you easy access to your search engines, so you can switch between them e...
Hi, there is already an option to show the toolbar only on the new tab page. Please see this support page for how to alter the setting: https://support.mozilla.org/kb/bookmarks-toolbar-display-favorite-websites
This is an issue caused by the ClearURLs add-on that will need their authors to fix it.
As a work around, you can disable the add-on, or perform your search directly from the address bar in Firefox.