I'd love to see an option in preferences under Units and Rulers to set the Ruler Origin (0,0) to be in a different location than the top left corner of the artboard, either on a document by document basis, or as a default - maybe with a toggle. A 3x3 grid of radio button selections such as top left, middle left, bottom left; top center, middle center, bottom center; top right, middle right, bottom right would be ideal, but a drop down list would work also. This would save having to zoom waaaaayyy in to the appropriate location and dragging the corner box of the ruler to (hopefully) line up with the exact pixel you're aiming for on each new artboard/file.
If there's already a simple way to do this that I'm unaware of, I'd love to know what it is!
"but the Action did not record my dragging the origin to the lower left corner." The drag or using the arrow keys when the move tool is selected puts Photoshop into a "follow on" or "reusable" action. Instead of recording "move one pixel down" over and over and over again Photoshop keeps track and just ends up with "move 4 pixels down." If you have actions panel recording you can see this, select move tool, move with arrow or mouse, then do something else, like select another layer, and you get two entries in actions panel, the final resting spot of the move and the layer select. If you can get the dimensions and location of the thing you are moving then just move it to "0, x" for left, "x, 0" for top. Does that work?
But I DO like the idea of a command that says, "move to the top" have you played with the alignment options in the move tool bar. Select two layers and pick: "Align vertical centers" that records in the actions panel.