I've played it through, but as a goodie. I don't do evil well.
Could an evil person not do good deeds in order to obtain access to greater evil? The Devil will do you a favour in return for your suffering. I see your point that the quests are all designed with a good charater in mind. The evil way out is to either ignore or kill them. Then you get little or no experience.
If it wasn't for the lack of experience rewards, you probably could complete Divine Divinity as a selfish, murderous [nocando]. Except you'd have to start kidnapping the Council members...
I need to stop thinking against my own arguments...
