Last night I successfully operated a tank (a Matilda IIRC) for the first time in CoD. Started in the gunners position, sight looks ok in model, but very low resolution, aiming is done with mouse and fire using the key set for secondary weapon (Space in my case). To drive you switch seat to the driver seat (press C is the standard I think) and then use arrow keys to go forward/back and turn left and right.
Unfortunately I couldn’t drive long enough to find any enemy, but it was actually quite fun even though it’s far from being a tank simulator, and I will probably try it again if I get a chance.
No multicrew? 
Not sure really, I think it’s possible, but haven’t tried it.
Ok, this is foreign to me is it a Mod how do you get into a Tank? You might want to try DCS Combined Arms, not much of a Tank Simulator but challenging.
It’s part of the patch from Team Fusion, nothing extra needed except a mission with it enabled. To drive a tank you choose it like you choose a plane and then just click fly.