First I would like to say that realism in a game is something that extends the lifetime of a game, and if something is too unrealistic I become mad when for example bottles doesn't crash when I hit 'em with my giant blunt weapon!
Here are my suggestions for some ideas that will add some more realism in game:
? Environment benefit/drawback/effects: slower in cold weather/snow, cold breath
? Protagonist voices: You can hear breath when fatigued etc., heavy armor sound (clinching)
? Less life overall because in real life you won’t survive like 50 arrows – then a better evasion system is required: A shield should block arrow and blade dmg, but blunt will destroy your shield.
If two blades for example hits each other they won’t deal any dmg but instead both will be staggered. Also a higher overall dmg for blunt weapons but lower evasion ability (or speed) when using a giant weapon.
? A hardcoe survival mode that requires sleep and food/liquid like in fallout
AND of course my example with the bottles