3) Ba'al is severely under rated in my opinion. He was never the "Hulk Smash" kind of Goa'uld, leaving that to cretins like Apophis and Sokar. He is the guy that figured out how to use clones to get around the annoying Tau'ri ability to ferret out plots. He is the guy who used astronomy, computing, and a Stargate to create a freaking time machine, and almost pulled it off if he hadn't over-estimated the reasonableness of his fellow Goa'uld. (He even appointed Teal'c as his First Prime in that alternate timeline, knowing that the dude was hella competent and would be happy to not have to work for a nutjob like Apophis.) He worked with the Tok'ra to figure out how to make the Ancient "kill everything" machine work on the replicators. He even appreciates how comfortable living as a 1%er on Earth is, and had no desire to destroy it -- just to conquer it (he is still a Goa'uld). He's evil as hell, but far more reasonable than most Goa'uld, and astute in a strategic, scientific and social sense.
So...take an insane genius who is smart enough to realize he's being possessed, and to use that as an advantage rather than get crushed by it. Give him a possessor who knows about Ancient tech and is used to thinking outside the box from a Goa'uld perspective. If I were to write a sequel, I can see that combination serving as a primary antagonist.