You can of course customize the toolbars [1] to remove the search bar, since you can also search through the address bar. But unlike the search bar, the address bar does not show suggestions as you type, because of the privacy implications of sending everything you type there to a third party. (There are add-ons to change that if you want to.)
[1]: http://support.mozilla.com/en-US/kb/how-do-i-customize-toolb...