[jsmith948]

Looking at your photos, it appears that you have two more holes left to move your pin box up (which lowers the nose of your trailer). On our stock 1621 Lippert pin box, the back edge of the "ears" of the frame to which the pin box is mounted are slightly below the back of the pin box and it hasn't been an issue.
We have about 8 inches of clearance between the bed sides and the fifth wheel chin.

As to how level the rig should be...I have seen many, many rigs on the road with a nose high fifth wheel. I don't know the formula for figuring how much each inch of nose high attitude transfers how much weight to the rear axle. The fact that the axles work together as a unit through the use of an equalizer would, it seems to me, negate or, at least, reduce this effect. Before you do a lot of work moving your hitch and/or your pin box up/down, why not go to a scale and weigh each axle individually? Then you will know for sure whether or not you are severely overloading the rear axle. BTW, I wouldn't worry about a difference in the weights unless it were more than a couple hundred pounds. JMHO.