No expert here, but here are my few cents. Unless reading wrong, it looks like your front axle weights with the trailer are only 140 lbs less than when unhooked. That seems ok to me. Ford recommends 50% weight added back to front axle. I run a bit higher than that to get better steering feel, but I'm not sure there is room in your setup to take "a few hundred pounds off the rear axle" without adding more weight to the front axle than when unhooked, which isn't really something that people seem to recommend now adays. Will the generator fit in the trailer somewhere?