Using your figures; axles are 3,500# ea. = 7,000# maximum on axles and 1,000# tongue weight. If your tongue weight is less and your trailer is loaded to GVW this means the axles are over-loaded, and most likely tires too. An equalizing hitch distributes the tongue weight between all tow vehicle and trailer axles, adding some tongue weight to trailer axles. Obtain your true weights ASAP, without them you are operating in the dark. Weigh tow vehicle loaded up ready to hit the road (don't forget all passengers, pets, and cargo), trailer the same way,then both hitched up so you know tongue weight on tow vehicle.
The ST (special trailer) tires should be inflated to sidewall maximum because virtually all trailer tires are operating at or very near their maximum load rating. Carlisle Tire goes further to state their warranty is voided if their ST tires are run at less than sidewall maximum.
BTW, the Tire and Rubber Industry says over 90% of all tire failures are due to under-inflation/over-loading.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"