Have a read through
this, a bit of a read, but there's a wealth of stuff in that thread. In short, you can change almost anything.
Gnome 3 doesn't seem to want people to use their mice, but rather the keyboard. I say go them one step further and stick to runlevel 3. With jed, alpine, mplayer, links, iwconfig, budgie, and transmission what you're all set.
Oh yeah, powering off will be in that menu, if you, either install the correct extension, or click on your username while holding down a certain key, sorry I don't recall which, play around and you'll find it, I'm on F14 right now. On F14 or F15, I just open a terminal and type
halt. Seems easier than clicking several times.
P.S. The key to hold down seems to be alt.