Nono, you've missed my point entirely. I've said it's a good idea to structure your points around these characters, but I've just said to indicate your broad overall point in the topic sentence of each paragraph, not to have something like 'The character of Bob epitomises the notion that self interest is likely to proliferate success, but consequently result in damaging an individual's integrity', but perhaps 'Throughout the play, the author reveals the notion that self-interest will inevitably sacrifice an individual's integrity. Through the character of Bob, we are given insight into...etcetc continuing about the single character'. And yes, obviously I have no idea what AMFAS is about or what it is, or if its even a play (I seem to recall it is though). It's just that I've been told VERY specific instructions not to include characters in the topic sentences and intro of a thematic essay by my teacher, tutor and in many English guides, as you're trying to address the theme in terms of the overall ideas the work presents, and then supplying evidence (characters) to back these up. But like you said, each to their own.
EDIT: Also forgot, the main problem with this is you're severely limiting yourself in terms of what you can speak about. A purely based character approach to a thematic question is often akin to digging yourself a grave since there should be much more other stuff you could use such as literary devices, stage craft for a play, cinematic techniques etc. It's quite hard to slot these in when you state your topic sentence to be about a character as opposed to an overall idea. Since theres only one analytical essay in the exam now, you're expected to show an overall understanding of the text in JUST this one essay, so you'll also need to bring in the context of the book, its overall themes, the writer's contention and well, characters of course.