Re: Firefox- Hidden Menu
That's not just Firefox, that's every program. It's one of the space-saving functions in the Unity desktop.
My recommendation would be to simply get used to it being hidden until you hover over it. However if you don't mind the chance of breaking your system (if you click on the wrong thing), there's a bit of a hackish way of doing what you want. I'll quickly outline it rather than give a click-by-click set of instructions:
1. Install the "compizconfig-settings-manager" package.
2. Run CompizConfig Settings Manager
3. Click on Ubuntu Unity Plugin, then the Experimental tab
4. Change the Menus Discovery Duration to something insanely large, like 1000 (it's in seconds), and the Menus Discovery Fade Out Duration to something even larger like 1000000 (a million milliseconds).
5. Changes take effect immediately. Close the window and DO NOT click on anything else, some of the options in this program can break your system if you even enable or change them.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.