So it's actually a feature that, if the PSS (TC's panoramic sight system) is in ALIGNED mode, and if the gun goes into loading position, the PSS switches over to show whatever the GSS (gunner's sight system) is using. I guess that's another 'safety feature' so that the TC can keep an eye on his gunner (?). Upon leaving the loading position, the original view should be restored (I've found a bug in that code though, thanks for pointing that out). In the PSS's OBSERVATION mode (ie independend view) nothing should actually change.
Hmm do you mean in multiplayer, that another player occuping the gunner's position hears the (AI) TC screaming commands? Or if you're in the TC position, you mean you hear TC sound samples being played?