Originally posted by PhoenixAsh
Sephiroth is HUGELY deep. If you believe some theories, he's deeper still.
Sephiroth is deep before he falls into the lifestream. After that event, any reasons he had before that justified what he was doing seemingly vanished. In other words, the past tense Sephiroth was a misguided villain and formed conclusions based off of inaccurate findings. The present tense Sephiroth wants to become God because he thinks its his right. Two very different ways of thinking there, and no bridge between the two.
Originally posted by PhoenixAsh
He didn't work for Baku, and there's no evidence that he knew the kidnap had anything to do with Cid. He never mentions it, Tantalus never mention it, Dagger is the one who wanted to go to Lindblum, and she is the only person with Cid when it comes up.
Ok, firstly, Zidane was a member of Tantalus, and therefore, he worked for Baku. In the Evil Forest, Zidane basically left Tantalus and no longer worked for Baku.

While in Tantalus, he was following Baku's orders which came directly from Cid who asked Baku for help in getting Garnet to Lindblum because the two of them go "way back" according to Cid, himself. So whether or not Zidane knew about Cid is rather moot. However, Zidane's attitude towards Steiner, and the fact that Zidane mentions never meeting Cid supports the idea that Zidane did not, in fact, have any knowledge that Cid was behind the whole thing.