WWdN: From chip leader to a disappointing 7th Place

After some excellent cards and excellent play, I took a chance on a board of rag-Ace-King with two spades. I had K-9 spades in the small blind. When S.t.B (Big Blind) made a raise (just the two of us in the hand; he had about 1/2 as many chips as I did), I decided to put him to the test, quickly figuring about 14 outs. I went all in with second pair and second nut flush draw. Alas, he had A-2 and no spades came on the turn or river. I went down to sixth place and hung around there until the final table with huge blinds. I went all in with A-7 and was called by S.t.B, who had ... K-K! I was hoping for an Ace on the flop, but a King sealed my fate.

The question: Did I take too big of a risk with second pair and second nut flush draw? Gotta think on that one.