Apart from the lack of sex, what other considerations are there when
It's not an easy thing to learn, to be able to make that transition from the live action show to the animated series. First of all, you have to be able to tell what is a one hour story in 22 minutes. You are asking people who have made their living the last few years telling stories that have an hour's length of time to do it in a half hour, and many people can't make that crossover - except the Buffy staff writers, who seem to be able to do it with their eyes closed.
The other thing is that in a one hour [live action] script, if Willow and Xander are walking down the street and they are talking to each other, you can simply say, "Willow and Xander walk down the street and they are talking to each other." Between the art department and the director and all those other people, they are going to come up with how they are going to populate the street.
In animation you can't do that - you have to say, "Two red cars go by, three people on pogo sticks are in the background and two old ladies will fight." You need to populate it all with what you want the artist to draw, or the artist won't draw anything and you'll have tumbleweeds coming through.
Fortunately, because Buffy is a visual show and because so many people on the show are comic book fans and have written for comics, it is the same kind of application of skills. You need to be able to explain to an artist in a comic book what's on the page in the same way you need to explain to an animator what's going to be in a scene.