I walk up to a door straight on our at an angle, SIG551 or 5-7 at hip, and I cannot open the door - even when it tells me that i can open it. I have to switch to a frag or knife to open the door. I believe it stems from the collision. Maybe allowing the gun to open doors would work.
Also going through doors that open upon touch them is a huge pain in the ass, you have to go in ass first. Or again, drop to your knife or 'nade.
Also one little cosmetic thing. The mirrors do not reflect your gun on your back.