JH Personally I like the Sith apprentice concept, although a bit wary of the 'pure evil' bit. Personally, I prefer shades of grey. The force sensitive soldier would also work. I think the Emperor would be aware of the program, although the program may be fairly low profile publicly. There wouldn't be any reason to make the character an Intelligence operative.
The way I see it, the Emperor knows that even if he knocks over the Jedi order, the universe will continue spit out force sensitive individuals. So better to have them on the inside, than free to establish their own order, perhaps along the lines of the Jedi, outside the Empire's control. The Empire doesn't present itself as evil. Publicly, it is a force for peace, prosperity and order. Of course, within the culture of the Empire, power is likely given a much higher priority than morality. But the Emperor, the Empire doesn't see itself as evil. Likewise, I don't believe that the Sith would necessary see themselves as evil. Rather, they would see their use of the dark side as the 'true' way to power. The dark side is a legitimate aspect of the force, like rage is a legitimate human emotion. To deny it is to deny the true nature of the force.
Why not start with what you like, and we can see where it takes us.
