Costs nothing but a little time to check alignment, then you know where you stand.
Jack everything up, so all 4 tires are off the ground. The take a can of light colored spray paint and spin each tire, spray a narrow strip all the way around the middle of the tread on each tire. Take a flat blade screwdriver and a block of wood to hold it against each tire and spin the tire and scratch a fine line in the paint with the narrow edge of the screwdriver all the way around the tire. Repeat on each tire.
Get an assistant and a tape measure. Have the assistant hold the tape fairly high up the front, then the back of each tire and burn one inch. Be accurate and measure width front and back - line to line - front axle tires, then do the back axle tires. The resulting measurements be reasonably close to square for each axle (don't care if the measurements are a little different between front and rear axles. only thing that matters here is the measurement across front and back on one axle at a time). At most you want about an 1/8 inch of toe in, meaning 1/8 inch less across the front of the tires compared to the back of those tires.
Second thing to check is center of spindle to center of spindle, left side and right side. Just hold a tape up to the center of the bearing cap and measure to the other one on the left side, repeat on the right side. These numbers should match pretty much exactly and tell you if the axle mounts were welded square to the frame.
It really doesn't matter to tire wear if the axles are straight to the hitch or not. That measurement is only relevant to whether the trailer is pulling straight behind or a teensy bit crooked. What matters is the tires are straight to each other. Anything off in the mounting or possibly bent axles, causes your tires to scrub the asphalt and wearing off rubber like an pencil erasure. If the toe in or out is excessive you will always have excessive tire wear until you remedy the problem. Measuring the toe in tells you what the reality is so you can choose how to proceed.
The above procedure checks toe in, not camber. Camber is set by how the axles are manufactured (or by damage from overloading or rough use) and is very hard to fix without a hydraulic press and some experience, or by swapping out the axles. Camber is also less important on a trailer as long as it is within reasonable. It is possible your axles were made with a lot of negative camber that is stressing the inside of the tires. If so, you either live with it or most likely change the axles. Swapping axles can be cheaper than changing the camber on them, depending on axle type and capacity, which determines cost to swap versus repair.
