1.Context hit. I don't know if that's the name, but what about having the hit location when you shoot somebody play an actual role. For instance, if you get shot on the leg, even if you survive, you won't be able to move properly for a while.
2.Executions. Also related to the context hit. One of your stretch goals was an advanced gore system. I don't know what this encompasses, but what about not killing players immediately, but having some sort of bleed out time, like in gears of war, in which you can get close and chop their heads off, piss on them, because why not, or even simply shooting them in the head up close and personal. The player being killed could crawl but not use any guns. Maybe allowing players that are in this state to get back up if in say, 1 or 2 minutes, they haven't been killed.
3.Wall piercing. Just as it sounds, I would not expect to gain any cover by hiding inside a military tent, but then maybe some walls or ceilings could be shot through. That way if you know someone is directly above you and you have enough bullets you could shoot him from the lower floor, and thus not exposing yourself to him camping upstairs waiting for someone to show up.
4.Blood trails. Say you are shot and manage to get away, but you leave a trail of blood behind, this could also be used for strategic purposes.
5.Dragging bodies. Would also be nice specially combined with the previous point, people could think there's someone hurt nearby, but surprise surprise.
6.Health regeneration. This is more of question than an idea. I wonder how this will work out? For me it would make more sense that you need some sort of bandages, but just wanted to inform myself
This is something one of our team members proposed a while back. In terms of priority, this is something waaay down the road but it was suggested as something we could offer in a seperate "Hardcore" mode.
Rust and RB Siege have something like this in terms of a "last stand" death approach. I'm personally uncomfortable with adding in any animations you can't control in a competitive multiplayer environment, but I can see how Rust's (Finish the job or help back up) decision prompt could add an interesting element to the game...
Wallbanging is something we're looking into. I'm 100% for it.
Working on some very cool ideas in terms of a "tracking" system.
This was suggested by a user on Facebook and we love the idea. Oh look, a body to loot! Lets take a look! /admiral ackbar
Healing will be very simple at first. Players can either heal themselves with medkits or drop them for a friend. Our inventory system only allows for a limited number of medkits to be stashed so players will need to use them wisely. You won't be able to load up on 20 of them and become invincible during the last stages of the match.