SC, I really hope it doesn't come to replacing the outboard bearings, you make it sound like fun.
I agree that it may not have oil at all, and that the sound is amplified with no suspension. It's not a bad sound, just amplified bearing and gear noise.
I'm going to change (or put in

) gear oil, and then just keep an eye on the temperature at the bearings.
Like you said, for my uses, failing bearings may last me years.
I, too, had thought the receiver slapping would improve with some tongue weight, but the compost didn't help any. I thought it looked front loaded, but maybe it was balanced over the axle. That may be a weakness of the design on this thing. It is light on the tongue.
Yesterday, on the drive home with the compost, I was going about 30mph in a 45 and had somone pull out right in front of me!

I hit the breaks and missed her by about 3-4 feet. Her eyes were big as saucers.

This old trailer saved her butt. If I had a new trailer I would have been going the speed limit and never stopped in time. geezzz. She was looking right in my eyes when she pulled out too.
The ball itself is a good snug fit, the slapping is my receiver in the hitch. Maybe I'll just hammer in a wooden wedge.