I have a scattered interest in lambda calculus too so I'd love to follow this project. Tromp's BLC definitely hits a sweet spot of complexity/size when it comes to describing computation in a way that's deeply satisfying.
Have you looked into interaction nets/other optimal beta-reduction schemes (there's a project out there called HVM)? Probably way too high level for now though. I am fascinated by the possibility of these algorithms making church-representations more asymptotically efficient (or even balanced ternary)
If you unnecessarily bring a gun somewhere and end up in a situation where you need to use it to kill people, you're a murderer. I choose to label that murder because I place him in the same category as convicted murderers in my head. He isn't some dude going about his life and needed to use lethal force in self defense due to unforseen circumstances. He actively sought out the situation, and therefore bears some responsibility. This is more a question of if you want to see his pattern of behavior encouraged or discouraged rather than a question about any individual's culpability.