This series includes several books. He does go underwater at one point, into the realm where King Arthur's knights await the time of their return, slays wurms, and generally does all sorts of do-goodery. The magic system is interesting, as all magic is fueled by karma, and is tracked by an Accounting Department to make certain people don't spend more karma than they make.

Yes, the film refers to it first as an 'unknown mineral' and is then later referenced by Ra, who states he is sending a shipment of 'my mineral' along with the nuclear device brought by the humans, along with the information that it would amplify the destructive impact of the bomb 100 fold(IIRC).

I can't remember what it was I miss the most... =p

I recognize it, but can't think of the title. I'll see what I can dig up.

The specific scene in the movie has them jumping out from a planet through a small fleet. If nothing else, the computer needs to verify there aren't any ships between their current position and their desired vector.

The tldr version: Rowling wanted Hermione and Ron to wind up together, no matter how much the characters had to be stretched to achieve that. There's also the fact that Hermione, for all her bossiness, has only two friends in the world*, as far as canon shows. That's the kind of thing that can leave you with a lot of insecurities, such as the ones she started with, before befriending the boys. *three if you count Ginny.

The only rational, logical progression from events shown to Vir becoming emperor seems, to me, to rely entirely on the fact that Vir is a close friend to Londo, and someone he knows can trust more than any of his court. That said, there's a quote from the Chronicles of Amber that I think is relevant: "I trusted him like I would a brother, which is to say, not at all."

It's been a long time since I last watched the episodes you are referencing, but there are a couple of answers common to questions like this. The most common: A) They didn't think of it. B) It wouldn't have worked for the setup the author(s) devised. C) They didn't have the time, resources, or inclination to act in this particular manner.