As for PCs and fully developed NPCs I personally have an aversion to single shot killing it tends to annoy most players (in my experience)
I'd agree here, wholeheartedly. I think that's another reason why I simply don't like CT and MT as a GM - I've never been able to get into the mentality of the players of those games where you can simply get blown to smithereens by a single, unopposed skill check and there's nothing you (as a player) could have done about it, and the Referee is like "Okay, the militiamen fire, and the guy with the fusion rifle ... hits Joe. *shrug* oh well, sucks to be you, Joe. Make a new character."
I like a certain amount of realism, but I don't like that much realism. I prefer games where players do feel a heroic impulse to do things like drag injured people out the line of fire instead of "Oh well, there's a guy with a fusion gun out there, forget it. Let my daughter die I can have another!"
It sort of goes to a pet peeve I've always had with a lot of sci-fi games - the question of armor and weapons. Players will always want to minimize risk and engage in it only to a minimum level. This means wearing the heaviest armor they can and carrying the most effective weapons they can. While it's fairly easy to dissuade players from carrying around plasma or fusion rifles, it's more difficult to prevent players from wearing as much armor as they can.
At some point, small arms become pointless against players. GMs have to ramp up the weaponry to threaten the players or ... ironically the players get bored (most players like combat and like it when there's a sense of achievement, not a situation where a bunch of guys in battle dress take out an entire TL6 Panzer Division). Then you run into the problem that's especially pronounced in CT/MT (but happens a
ton in TNE as well) of "ding or splat" - in other words, the attack either glances off harmlessly without ever having a realistic chance of presenting a sense of danger to the player or it penetrates the armor and the player is transformed into a fine red mist. There is no condition in between. This, in turn, creates the "arms race" situation. Once one guy in the party has such good armor, as a GM, if you want to challenge the players with average combat, you either need to ramp up the weapons to deal with the well-armored guy (with high death rates amongst those without such good armor), that one guy basically can be victorious in every encounter without fear ("send Joe in!"), you have to somehow take the armor away, or you have to give it to everyone.
That TNE tried to address the situation a bit made me like it.
