I prefer the address bar on the bottom of the page it makes it easier to catch spelling mistakes as I’m typing , you can have any toolbar on the top ,bottom left or right of the page.
Other options for toolbars include being able to select having the tab bar use an extender menu or wrap the tabs to multiple lines , useful if you are stupid enough to always surf with 300 open tabs.
The best option for control with 300 tabs would be to open the Windows panel.
Opera is head & shoulders above Firefox for customizing the user interface when you download Opera you have multiple options in the installer including being able to install it to a folder as a portable version.
My favorite feature is the integrated Mail another is being able to right click on the page for the context menu & select the open with option & choose from your installed browsers to open the page very useful lately with Opera 12 site comparability has never been worse.