I completely agree with you. All these are considerations I made through development. For example, I considered giving suspects different roles (an accomplice who protects the killer, a person with a grudge who will always lie to frame somebody who is not the killer, a forgetful suspect who doesn't provide any useful information etc) plus more types of weapons and clues, but unfortunately this is all I managed to do with the time allotted. Time management is a skill in itself with these jams, and I'm not too good at it (yet! :p)
Thank you for you kind words!