Honestly I would like to see the Environmental hazards if nothing else. Even Minecraft had it right when it says don't dig straight down! Plus visions of mining Iron ore right next to a gas pocket.... tink... tink... tin..BOOM!!!
Other than that I would love to see gate crashers, sleepers, and...
Must admit that while I think the HP bar will break the immersion, I will more miss the ragdoll effects. With that I did have some where i was like "WHY DONT YOU DIE!!!!!" after the 6th crossbow shot to the head area (might have missed a few). But most of the time I could tell even sniping a few...
I want to start this off by stating that this is a question on game mechanics i.e. where the data is placed in the code or how the game calculates the values.
Explanation
With the above stated, I was looking through the .xml files trying to do calculations for mid/end game tools and seeing...