She's a sixteen(?) year-old, that's understandable. It's not like the other teen ruler protagonists* in the series haven't done stupid things. I like that she's a flesh-and-blood girl with urges and moments of childishness and not some alabaster ideal queen.
*
Spoiler thinking of Robb and Jon, are there others?
Joffery for one, Viserys for another - but they're not protagonists they just do stupid things

While I understand the basic concept of what Varys means, how exactly does he find the idea of Stannis Baratheon being just a 'terrifying man'? Is it because he does what is lawful regardless?
"There is no creature half so terrifying as a
truly just man"
He is found terrifying because he is incorruptible, he does not sway to the tears of women or the begging of men. What is treason is punished, what is his duty he will fulfill. He believes in the laws of the land and does not bent them or break them to suit his needs, he's pretty much an iron rod whereas the other characters are http://t3.gstatic.com/images?q=tbn:ANd9GcRETHU57r_3cY8CEsmp0UNLjKoqbdQzdsgiFT3AunURp6EtqOhH.