I resisted lubricating the L brackets for the first two years I owned my equalizer as I didn't want to deal with the mess, and was constantly fighting the L brackets walking along the frame. Last year I lubed up the L brackets and they did not walk along the frame at all, in addition to a much quieter hitch. With the Equalizer hitch, if you are redistributing a lot of tongue weight you can end up with too much friction and lubing up the L brackets has made the hitch much easier to live with, even if there is a little bit of a mess; it doesn't take very much grease, just a thin film.
I'll put in another vote for not leaving the trailer alone where it can take off and hurt or kill someone, the best chance of keeping it in place is hooked to the tow vehicle. So what if you have to wait for help, think about the other people on the road.
Another vote for putting the corner of the trailer against a hard object, I've seen it done, and it works. In this case the steer tires were the only ones that would actually lock, therefore the driver did a really good job getting the back of the trailer into the bank to stop the backwards skid/inability to hold load on grade, the result of a missed downshift.
Another reason for anyone wondering why you need 4x4. I use it off road, but I'll also use the extra gearing whenever it's needed. Dry pavement? I've scrubbed tires, but never had anything break, that's why your front and rear diffs are geared the same, and you run the same size tires. Even switchbacks are very rarely sharp enough to require full steering lock, where something may break from the different paths the front and rear axles are taking.
Don't be afraid to back up to safe spot, with a spotter to warn traffic. If you can drive forward into it, you can back out of it.
Where are the diesel fanboys now? (OK, I couldn't resist) I've too been humbled by a grade, but at least it was 15%, and I made it without having to resort to low range. It's amazing how much a few percent and a little elevation will change things, so you may never find the elusive gremlin in the machine, it may have just been the conditions of the climb.