Most of screens come from after battle when you get the free cam. As neato as it would be, an all powerful god camera in sabow would totally destroy the tank sim aspect. Unlike APOS where only units that are spotted show (unless you have it set up for show everything........total cheat IMO) it renders all units at all times as a tank sim should.
As to the second part. Right now no decent way to do it. The easiest is to go in configs and change stuff around and use the interior model of t62 or m60. It LOOKS TOTALLY AWFUL and you have no functionality with commands. Sooner or later someone could model a basic interior of other tanks in sabow and figure out how to configure the weapons and sights to be playable. But learning curve to do all this is huge and vary time consuming.
Oh another thing.... I keep hoping Gravi will will add interiors to at least the oliphant (south africain centurian). I keep asking for a playable bmp1 so I don't think I have much pull on that.
. Maybe an addon dlc? Or a SABOW 2? Hmmm who knows.