I can definately understand how both parties acted though. It's unhappy to think about harming such wonderful little ratties for ANY reason, but snakes do have to eat. I think that if it has to be done, then try to do it as humanely as possible. I always think of it as the animal is giving its life to help another, and I think it's necessary to thank that animal for it.
I'm glad to hear you're holding off on things for a bit, to be honest. Even without the wishy-washy topic of morals, that's a lot of stress on yourself! If you can avoid it, then it's better! I think that for any situation!
Good luck. I really hope you can still enjoy this community, because it really is a great one!
ETA: In case you haven't seen this before,
http://www.dapper.com.au/cagebuild.htm is a great page for building your own cage! I think you have to be conscious about the stink potential with using wood, but I think melamite is different? You'd need to look into that though, cause I'm not sure.
I honestly thought that Co2 was humane, but after reading how a human tested it on herself, I know differently.
I think the important thing is you know now. No one can say badly of you, because we're ALL constantly learning, it just so happened yours was a bit more of a touchy subject than some, you know?
ETA 2:
Riana, thanks for that. Actually I have looked into other options, and found on a pet rat site a method that is supposed to be humane. I asked snake owners if it would harm the snakes and I got a not so nice response.
Given this experience, if you were to pursue things, it may certainly be more beneficial to look into talking to a vet. The vet would have the best interest of the rat/mouse in mind, AS WELL as what's best for the herp.
Ok, enough second-reading posts