If the BTR-K is based on the BMPT-64 then you are right. The engine should be in front.

However I am not sure I am able to see the engine in thermal (on the BTR-K as well as the other APCs). I can only see the exhaust outlets that are hotter than the rest and of course the guns when firing. Maybe my settings are messed up.

While it is true that the turret is remote controlled, you can clearly see three separate hatches on the top hull of the vehicle (unlike the Panther for example, which has only one hatch for the commander to turn out from). That leads me to believe that the gunner can indeed turn out.

Even if the gunner cannot turn out. Having that ability for the commander at least is very essential. It will also make things a lot less painful for the driver as well.