I think some improvements too melee would be nice it's been the same sense alpha 8, and only with 17 they added the power attack. Some new animations from swinging the weapon side to side would be great. It doesn't have to be dying light levels but more like skyrim or fallout 3. Still simple but slightly better animations
Attack, heavy, block.
And in terms of zombies. I think they talked about this but. A headshot only setting would be really cool. Something the game Really needs is zombie variation and modifiers. Maybe increase spawns, increase wild zombies difficulty and types like the wasteland all biomes.
Have a special were he only dies when you chop all his limbs like a necromorph. Have a healing zombie, have a bomb/gas Zombie. Ones that climb. With the new animations coming in for animals. Seeing it for zombies would be great and even better if they added a climbing animations. Doesn't have to be special. Just Make it so he looks like he's climbing a ladder.