Kelsier always struck me as a psychopath, also that he was honestly too afraid to pass on. He wanted a project to remain important, relevant and maybe becoming a cognative shadow somehow enhanced his desire to survive.
I think he’s paranoid and power hungry and the GB strike me as having a relaxed structure. Like his old thieving crew of mutual benefit and gain amongst its members.
I think other posters have elaborated on what we know of his and the GB goals