What about creating an ACTUAL Dark Knight?

[HWalsh]

Fairly sure this one is true about cecil.
The rest is based on other iterations of DRK in either mainline or spinoff titles.

Nope. I've played FF IV a LOT and Cecil doesn't do this. He casts some damaging spells (Fire - For example) but that's it.

He uses "Black Magic" hence Dark. When he becomes a Paladin he uses "White Magic" that's all it is.