As other have said, look under the trailer and see if your axles are curved up or down in the middle of the axle. If they are cambered up, the axles haven’t been overloaded. If they are cambered down it could have been overloaded before and that would make the tires wear on the inside bad. I had a boat trailer that did that with wider tires than what came on it. I would also check the leaf spring and metal brackets to make sure they aren’t wore bad to give the axles slack to try to walk back and forth. I would remove the ramps because they will definitely act like a spoiler at speeds over 35 or 40 mph. Living in florida with fairly flat ground, you might be getting close to the max weight your truck can tow, but you don’t have to worry about going up or down a steep grade. If everything checks out fine, I would put some more weight on the tongue.
