In terms of gameplay mechanics, old school zoom aiming achieves the same thing as ADS. Is getting to press your nose against virtual firearms really that important in a game about shooting werevolves and vampires?
I blame this on the proliferation of Call of Duty over traditional scifi and fantasy shooter franchises. You can fucking ADS on an assault rifle in Halo now
i like contextual animations, you could also use a bunch of contextual radial menus for stuff that isn't immediately necessary to free up controls. mostly contextual animations could be better i think, they only even try that approach in 3rd person games.
for camera bob and motion sickness, i think the camera in FP could just not be directly physically attached to the player model, or have a zone inside the head (which is not rendered like in ARMA or perhaps behind the camera) in which the camera can move freely to stabilize itself. or a combination of approaches. i think battlefield games usually have realistic looking run animations sometimes by just rendering a different model in first person with just legs and putting the camera in the chest (arms and weapon drawn on the HUD layer). playing GTA4 with first person mods didn't give me any motion sickness at least except maybe during car crashes. animations don't necessarily have to be physics based either, handmade or edited motion capture animations done well can have similar visual effects.