-Permanent death (if you don't surrender fast enough) would be a nice feature for, let's say, "Hardcore mode" , i can only sympethise with that idea.
Maybe something like that could even be integrated in some kind of small multiplayer-progression/ladder mode, where equipment can be earned, but death means loosing all.
-New MP-modes would be nice too. Like a "Gungame-Battle" where you spawn every round you killed an enemy, with a better weapon, with the goal to be the first to kick someone to death (which would be the last level, to win the mode and than mapchange). Not authentic, but surely something to attract the masses... Or a tournament mode with randomgenerated duell-partners in arenas.
- Hacking your enemies bodyparts away is a nice idea but would lead to a higher age-rating. See Chivalry with the PEGI of 18.
So, from a sales-viewpoint, it's quite a bad idea (but i trust in the modding community

) And there is the decision Gore vs. Battlesize. Hacked bodyparts must use some kind of physix = cpu usage. I'd rather prefere 200 more fighers in the field for the performance down, than seeing arms and legs fly... well... mostly... in the long run... after beeing very sadistic for a while.