I worked on ArmA2, unfortunately as a 3d artist I didn't have much input on gameplay features... So I will now try to push the features I was suggesting there onto RO2 
* Leaning inside tank
It is hard to see out from a tank, everyone knows that. However games make it even harder than it is in reality by having your viewpoint bolted to the chair. You can perhaps look around, but your viewpoint does not change. In reality, a tanker would have no problem to lean to side to get better view. When you turn your view left, your viewpoint would move to right to get better view to left side. You could move your viewpoint up and down in similar way, so that there would be less issues with looking into ground or sky when driving over bumps. Also moving viewpoint would prove that the tank interior is truly 3d and not just some kind of panorama texture.
*Leaning forward
When on elevated position with railing you often find your ability to shoot/see below very limited, because you can hardly get right next to railing (because of hitboxes), let alone bend over it like you could in reality. Granted, bending over railing exposes you a lot, but that's not a reason why it shouldn't be possible. As lean forward might be a bit clumsy, it could be implemented as natural part of aiming downward (when you can't aim from upright anymore, you bend over) or a part of cover system.
*Excessive sway and recoil when not prone
Sway and recoil in RO:Ostfront when crouching and especially standing are extreme in comparison to when prone. I'm not gonna argue realism of that at this point. The main problem I see is that it promotes everyone fighting and even moving around prone, greatly slowing down the pace of game, which wouldn't be that high to begin with.
*Realistic range of engagements
This is related to previous issue. While enemies in RO:Ostfront might seem quite far, because of high FOV, they are not. Most combat occurs at ranges below 100m. I hope this will be improved toward realism in RO2, because real effective ranges are 200m for SMGs, 400m for rifles and 800m for sniper rifles.
*German tanks are better at long range than Russian tanks
I would really like to play a map where German tanks, particularly Tigers, could fight Russian tanks at range and demonstrate their superiority in such scenario, by obliterating T-34s by dozen. While it would certainly be unfair to Russians, there were several rather onesided tank battles in RO:Ostfront.
*Excessive fog
If you look up Stalingrad/Volgograd weather reports you will find out it is actually drier and sunnier than most places in Europe. Period photos mostly confirm this:
I hate the feeling of blindly roaming through endless fog which some RO:Ostfront maps give. Crazy fog like that made sense 15 years ago when computers could handle only limited amount of geometry - what purpose does it serve now? If you absolutely have to make a map with thick fog, at least take care that the fog is well-matched with the background. That it doesn't look like there is more fog in distant parts of the map than it is in skybox. Something like that immediatelly makes the scene look fake. Fog and horizon should blend together nicely.
* Leaning inside tank
It is hard to see out from a tank, everyone knows that. However games make it even harder than it is in reality by having your viewpoint bolted to the chair. You can perhaps look around, but your viewpoint does not change. In reality, a tanker would have no problem to lean to side to get better view. When you turn your view left, your viewpoint would move to right to get better view to left side. You could move your viewpoint up and down in similar way, so that there would be less issues with looking into ground or sky when driving over bumps. Also moving viewpoint would prove that the tank interior is truly 3d and not just some kind of panorama texture.
*Leaning forward
When on elevated position with railing you often find your ability to shoot/see below very limited, because you can hardly get right next to railing (because of hitboxes), let alone bend over it like you could in reality. Granted, bending over railing exposes you a lot, but that's not a reason why it shouldn't be possible. As lean forward might be a bit clumsy, it could be implemented as natural part of aiming downward (when you can't aim from upright anymore, you bend over) or a part of cover system.
*Excessive sway and recoil when not prone
Sway and recoil in RO:Ostfront when crouching and especially standing are extreme in comparison to when prone. I'm not gonna argue realism of that at this point. The main problem I see is that it promotes everyone fighting and even moving around prone, greatly slowing down the pace of game, which wouldn't be that high to begin with.
*Realistic range of engagements
This is related to previous issue. While enemies in RO:Ostfront might seem quite far, because of high FOV, they are not. Most combat occurs at ranges below 100m. I hope this will be improved toward realism in RO2, because real effective ranges are 200m for SMGs, 400m for rifles and 800m for sniper rifles.
*German tanks are better at long range than Russian tanks
I would really like to play a map where German tanks, particularly Tigers, could fight Russian tanks at range and demonstrate their superiority in such scenario, by obliterating T-34s by dozen. While it would certainly be unfair to Russians, there were several rather onesided tank battles in RO:Ostfront.
*Excessive fog
If you look up Stalingrad/Volgograd weather reports you will find out it is actually drier and sunnier than most places in Europe. Period photos mostly confirm this:
I hate the feeling of blindly roaming through endless fog which some RO:Ostfront maps give. Crazy fog like that made sense 15 years ago when computers could handle only limited amount of geometry - what purpose does it serve now? If you absolutely have to make a map with thick fog, at least take care that the fog is well-matched with the background. That it doesn't look like there is more fog in distant parts of the map than it is in skybox. Something like that immediatelly makes the scene look fake. Fog and horizon should blend together nicely.
