Nice rig Eric! On the shocks i love how my bilsteins control the truck with a trailer and also when plowing i weight 12000-13000 (truck only) they do great. I drive customers trucks all the time who have Rancho's,and IMO they dont last but a few months,and they cant control the truck anymore.
On being overweight,If i were you,at the minimum I'd re-register the truck for 11000Lbs,and make sure the registered GCWR covers your actual weight when fully loaded. If needed, a good attorney could argue that you are below the limits of the weakest links,axles and tires,and therefore you are safe in the eyes of the DOT,if its good enough for them,it should more than satisfy there requirements. Also maybe get a letter from your insurance if you can to ensure you will have coverage at that weight. Anyone can be sued ,even if your under 8800. You just want to ensure your insurance co will be there if needed.