If you expect to get anything done without using the mouse, knowing all the "special key combinations" is a pre-requisite for any OS. I hate to be the kool-aid drinker that jumps to Apple's defense, but I hear a lot of complaints about OS X keyboard accessibility that simply aren't true. A single checkbox enables access to "all controls" through your keyboard. It's turned of by default because, frankly, most people don't use the keyboard. I do, but my computer is my instrument.
BetterTouchTool might even do everything you need, but I'm not completely sure about that.
Not being able to dismiss a dialog box with the keyboard was driving me mad.
System Prefs>Keyboard>Keyboard Shortcuts>"All Controls"
Seriously.
It was hard to find both times.
kb
Enter = Ok, Escape = Cancel, Command-D is "Don't Save" in "Would you like to save?" dialogs, etc.
I'm still getting a ThinkPad for personal development projects, but my work laptop just became much more usable.
command + ~
when you get that going with the command tab switching you can fly!