I'm picking up the idea of the "Damage Volumes" thread because I had an idea before. I thought it's better to make a new topic since this idea goes a bit deeper than just a comment in the other thread.
I guess there are many who wanted to have a hurt-material, so it isn't a new idea. When I wanted to use it, I thought that if there was a hurt-material, there would be other martial requests because people come up with more than that.
So basically, this is just a concept idea and nothing like a perfected suggestion.
What if the materials weren't preset, but they would work like textures. There would be a default material-configuration, and the possibility to create your own map-specific material configuration in the map cfg file (after using materialreset, similar to texturereset).
The player could give every material a name and define its functions, for example how much damage it causes, if it's clipped, if it's water, lava or air, the color it has and so on. It would allow you to easily merge two materials like water and death. I'm aware that it's already possible to add two materials in the same area, but it would be a lot simpler and less confusing to not have two overlapping materials, but a self defined "water-death" material (or however you want to call it in your cfg).
It could also be possible to make the material execute a row of commands, for example kill the player after or keep damaging him during a certain amount of time, or make him drop the flag - it would be up to every mapper to create his own materials.
The water, air, noclip and other commands would be replaced by something like /addmaterial [slotnumber], and the material menu would adapt itself to the material configuration, i.e. adding a guibutton with the chosen name of the material that adds it to the map.
I realise that most likely there won't be someone who's implementing all this because I suggested it, it's rather just an idea that you can think about and leave a comment if you want.