"In conclusion, both the soul, who we are, and the spirit, our universal capacities, continue to exist after death. ......thus we continue to exist as ourselves after we die."

I didn't wade through your supporting argument but whether it was logical or not the above section of your conclusion is totally in accord with fundamental teachings of Modern Spiritualism.

Maybe right for the wrong reasons but no less right for all that.

I've been passing on a similar message for quite some time. Not quite 'as old as the hills' but certainly nothing new....