I could have, but didn't use any feral addons. I only played kitty for about one month before Cata, and I'm pushing against the theoretical max DPS in most fights. It was certainly more difficult pre-Cata, but aside from learning it for about a week and then adapting it to specific encounters, I didn't find it all that challenging.

If I were to have used an addon, it would just be to learn the rotation. I'm pretty minimal with timers as well (only use Quartz), and simply prefer to read some theorycraft and practice, practice, practice.