King Tiger...
Both the Ju88G-1 and G-6 had air vents in the fuselage, but it was less common to see this on G-1s. The initial G-1s had an air vent in each wing, close to the wing root. The fuselage vents became standardised on the G-6 and the wing root vents were deleted on this version.
The 'window' in photo 3 is actually an access panel. It is part of a blister on the fuselage side, and may have given access to the forward fuel tank (480 ltr) which was positioned inside the fuselage at this point. It appears to have been removed on the aircraft in the photo at the time it was photographed. I don't know why there would be two panels. I am only aware of one being positioned at the front of the blister.
As for the camouflage colours... sorry, it just looks too confusing to believe... ! I could hazard a guess, but would most likely be very wrong...
Hope this information helps.