two left feet... yes... you're right on that one. Though for spineless at least I can say that this is a LACK of a body part, not HAVING or BEING a body part, which is what the instructions stipulate.
I guess I could add "backbone" and say something about stubbornness or self-confidence. Probably not stubbornness... that would be more like having a hard head.
I would agree that having heart can mean that you are tenacious, that you never give up, but I don't think I've heard it mean that you are audacious. There are different kinds of bravery. The sort that you would need to do something that would be potentially socially embarrassing... like ask out a girl way out of your league or sing My Humps at karaoke night, or make a statement publicly that you know will be unpopular, that takes balls. Not heart. At least that's what the word connotes to me. I would say that having heart is more similar to having guts- bravery in the face of impossible odds or potential physical harm. But the definitions are all pretty similar and of course there's some cross-over. I tried to make the best of it.