Having been down this road, I can give you a quick check that will tell you if your axles are out of alignment. Measure from hub to hub on both sides. The measures should be virtually equal, maybe 1/8" difference but not 3/4" like our trailer was. Also take a level and measure each wheel vertically and horizontally. Again the measurements should be virtually equal. The vertical will probably be off of straight perpendicular but the difference on each of the wheels should be the same.
We noticed the tire wear problem like you noted and that was when Lippert was having to replace a lot of axles. Our axles were OK but they were out of alignment by 3/4". That caused a lot of tire scrubbing when we were going down the road. Althought it was not that expensive (about $100 ten years ago), the manufacturer reimbursed us even though we were out of warranty by that time.