Need Feedback ASAP - Questions about Towing

Take this with a grain of salt, but if your cargo calculation is in fact accurate: over is over. No way too know without weighing the rig, but I would want to know if the rear TV axle is overloaded. As far as the hitch rating you will find that stamped on the TV hitch itself. Should have a non weight distribution rating and WD rating specified. You didn't really ask, but I would not consider a marginal tow vehicle purchase when I already had the trailer.
Many tow at or over some of the TV specified limits. I prefer to remain well within the ratings. All IMHO...