Understand, and agree on the legacy - I've thought for some time she was the most important philosopher of the 20th century, IF one agrees that she's a philosopher (many wouldn't... I go back and forth on that one, but she's at least as philosophical as Marx, and more helpful if far from perfect). I'd also argue that her philosophy of radical individualism has been nearly as important, if unacknowledged, to the Left more than the Right - for too many today, the 'virtue of selfishness' = Do Your Own Thing, Ask What Your Country Can Do For You, etc.
I'll bet if you dug a bit into the background of American entrepreneurs from 1970's to the turn of the century (e.g. the INC Magazine crowd), you'd find a lot of people who read The Fountainhead and Atlas Shrugged (even if it was a long time ago).... the socially liberal / economically conservative group who are now more likely to vote Obama than Romney. Why is that so?
Where the 'Right' is more likely to get confused is on the coldness of economic calculation vs. a sense of common decency (in this respect, the Romney Video is most painful - plus the math is wrong!). Where the 'Left' is more likely to get confused is disconnecting freedom of choice from responsibility (why we keep coming back Sandra Fluke and her pathetic plea for free birth control). The personality, as manifest in her novel's cartoon characters and consistently strident tone, is important. It has limited Rand's influence, both on the right - the coldness towards other humans very much inspired the Whitaker Chambers takedown in National Review, an important touchpoint that you have rightly cited several times - and on the Left (numerous dreary Krugman and sub-Krugman columns bemoaning radical *economic* individualism).
Just my thoughts. The Heller book is very good. A hilarious parody of Rand may be found in Tobias Wolff's great prep school novel Old School (a faster read than Heller).