This is a beast of an aircraft and I'm sure the end result is going to be spectacular.
My comments and advice;
We tend to show all doors, undercarriage doors and bomb bay doors, ailerons, flaps, rudders, elevators outlined in black, basically anything that can be opened or moved but small items such as inspection panels etc. I agree at times the black looks odd cosmetically, especially bomb bays for some odd reason. Since you have the rudder etc. in black already it might make sense to make the bomb bay black outline too, but I think a slightly darker grey would suffice quite nicely.
I would redo those leading-edge intakes, I'd draw them as black outlines with a dark grey filling, or a dark grey infill with darker grey outlining. I feel in either case the current grey is too light to show they are deep, dark holes.
You might want to outline the main wheels in black like the nosewheels, they are slightly egg shaped (2 pixel wider than tall), I guess your going for a 'flat-tyre under load' look which is no bad thing. Maybe a 25 x 26 pixel would be better.
Reflective metal skin is going to be bugger to get right, especially when you start dealing with shadows etc. Of the two small examples the one on the left looks better but I still feel its going to be too many different shades. As we discussed with your monitors the effect might just make the B-36 look like a giant hexagonal flying tube rather than a reflective tube. I wonder whether a simpler way would be to repeat a 3-pixel layer of the top-shading colour 3-4 pixels beneath the top shading to give a cylindrical-type shine. A few non-SB style drawings have used that. I've tried a tin portion of your B-36 with it and it looks ok.
Here is a small test:
A parts sheet of the various bombs would be great!