I'm still fairly new to SS13 but I DMed/Developed for a NWN persistent world RP server for 5-6 years. Making players fear death was a pretty big issue because clearly people were not on our server. And after struggling with it for a long time, I've come to the conclusion that you have to pick your battles and this particular hill is not one you want to die on.
Players don't fear death. They fear boredom. That's why players are always going to charge into dangerous situations. Because sitting in a locker instead is boring. Safe is boring. A server full of people doing the safe thing is boring. People won't play a boring server.
It's okay that people are reckless. Chock it up to the fact that the type of person who signs on to work at a deep space plasma research station in a world of cults, space carp, vampires, shadowlings, changelings, terror spiders and Xenos are probably not people who shy away from danger. We're all a bit crazy if we decided to be on the Cyberaid in the first place.
As for Cloning roleplay, the problem here is that mechanics and roleplay are in conflict. Fixing this problem means putting the two back into sync.
When I play MD, my patients are real players with their own agendas and their own things they want to be doing. Now occasionally, you get the guy who wants to RP his trip to Medbay and those players are great and I will definitely take the time to chat with them and tell them what is going on, ask them how they got injured and describe the treatment I'm giving them. But, often I will have a patient who has things to do and they just want me to fix them and get them back into the round as quickly as possible.
And this is why the Cloning versus Treatment debate is more like a balance than treatment being always the correct choice. Yes, I will roleplay that Cloning is a last resort because it means the person died and a replacement is now walking around. But at the same time, if I have a player who just wants to get back into the round, and I know I can get him back into the round twice as quickly by cloning him as I can be reviving and treating him, is it really right for me to force my own roleplay preferences onto them, to enhance my experience at the cost of theirs? I'm not so sure it is.
The solution to this problem is to change design so that the roleplay motivations and mechanics motivations lead to the same behavior, rather than different ones. This can be done by either changing roleplay or changing mechanics to bring the two into sync.
To change it mechanically: if we want Cloning to be a last resort in terms of roleplay, then it must also be a last resort mechanically. That is, it must be the most difficult and time consuming way to revive someone. How exactly to go about accomplishing that, I'll leave to people more experienced in ss13 mechanics than I am.
To change the roleplay: Give roleplay reasons to clone over treating. For example, add fluff about how science proved ghosts exist and migrate to a new body. Or make NT SOP say you have to use the least expense and time consuming methods of treatment and even though we don't like it, we all signed the NT contract so we have to do it.
My preference would be to fix it mechanically by making cloning more time consuming and difficult. When I play MD I want to do more than just throw people into Cryotubs or Cloners. I want there to be a reason for long, complicated surgical procedures.
That said, it's less work to fix the issue from the roleplay perspective, and while doctors might like longer and more complicated treatments, patients typically don't.