A forum centered around the MBTI might be a bad place to start this topic, but has anyone here read it? It's great stuff.

I suspect the writer is an ISFP.
I get the impression the anime and manga world is dominated by ISFPs, in the same way that the literary world is dominated by INTPs and INFPS.

What are your thoughts on the characters?

Alpha herself is an ISFP, I'm quite sure.