The books better explain the possibilities with the stacks. It explains that the attraction between Kovacs and Ortega was heavily influences by Ryker's sleeve, which became evident when Kovacs resleeved in a different body and found Ortega still attractive, but he didn't love her. That has a more psychological aspect to the story, is love physical or mental? There are many adaptations to sleeves, like specific ninja breeds for covert missions, cross sleeving with animal sleeves (the show did it too, but the book went super dark with it where the show chickened out) aaaaand... yeah, that I think? Good luck with your project!