Second: it was not as bad as you had feared, but as a whole you did fall for the straightforward-but-mathematically-tedious traps (problems 2 & 6, mostly). The alternative was problems 4 & 5, which were very simple with little calculation if you remembered what to do.
Third: here are some interesting plots.
A few little things I found interesting:
- You did very well on #1, which means you really looked at the practice problems (it was the same).
- Only #2 was strangely low; it was hard, but it was also a homework problem (HW5).
- A surprising number of people chose number 6, despite it being the obvious trap on this exam. It was straightforward, but a serious time sink. Myself, I would have skipped it. I graded fairly generously on that one if you had algebraic issues but the method was basically ok.