Questions that popped into my mind from Revenge of the Sith

After watching Episode III, there were some nagging questions that I had no answer to. Perhaps I need to read the book, and I plan to, but until then, these questions remain. This contains SERIOUS SPOILERS about the movie, so if you haven't seen it, I would recommend not reading this. As a courtesy, I will attempt to invisiblize the text, so to read it, highlight it.

Question 1: What horrible malady did General Grievous have?

For the whole time that he was on screen, he seemed plagued with fits of coughing that seemed somewhat painful. Did he just have a cold? Maybe some bronchitis? Was he a heavy smoker with Emphysema? Perhaps he just needed a Halls.

Question 2: How come Leia could remember her mother being beautiful yet sad, when Padme keeled over in childbirth?

This was the prime reason I was convinced that Padme was going to live beyond the end of Episode III. Leia had memories of her mother, while Luke had none. Naturally, Padme should have gone to Alderaan with Leia to hide there for a time, before dying when Leia was "very young." Now, the Episode VI dialog doesn't really make sense.

Question 3: Why didn't Obi Wan finish off Anakin at the end of the movie, instead of leaving him there to suffer and presumably smolder to death?

Obi Wan seems especially callous on this one. I can understand him being choked up about killing his friend, but really, he had already lopped both of Anakin's legs off, and he let Anakin slide down to the point where he was engulfed in flames and writhing in pain. The only humane thing left to do was to get down there and finish the job. Of course, then we wouldn't have any Darth Vader, so that wasn't REALLY an option. But perhaps Obi Wan could have been driven off by something or someone, to explain his abandonment of his former friend.

Ok, I know that I have more questions, but I can't think of any right now. So look for an update to this entry when my brain finds me again.