Interesting. I would like to meet this person. I find it very helpful to surround myself with people that have a different way of seeing the world.
I would like to meet this person. No, no no no no. No you would not. Not unless you mean it like "I'd like to meet a serial killer, just for the experience." Maybe it'd be interesting to get their point of view, sure, but you are far better off without them in your life. And certainly without having any form of relationship with them. One of the main reasons this guy wrote this letter was probably self-aggrandization…
Honestly, did you read the entire letter? Because he clearly address that point:
Its true that I do not 'feel' guilt or remorse, except to the extent
that it affects me directly, but I do feel other emotions, which do not
have adequate words of description, but nevertheless cause me to derive
satisfacton in developing interpersonal relationships, contributing to
society, and being gentle as well as assertive.