How do you nudge objects and props, by a keystroke up, down, left, right?

I use the parameter dials for moving things. I dont know of any keystrokes that do it . 

Parameter dials are so cumbersome. There are has to be some more elegant way to nugde things around.

you can select the object, and then use transform tool of mouse while holding down shift key

You can turn the sensitivity for parameter dials to whatever you want (often I set it to 1% of its default value, for translation) and they stop being so cumbersome.  Double click the dial and change the Sensitivity value, e.g. if it's 1.0 make it 0.01.

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Attached Link: Arrow-move

Here's a very old script that lets you move the selected actor (a prop, a camera, or a BODY of a figure) by using the arrow keys.  

I haven't tested it in Poser 8, but it's probably OK there.

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Keys, at least in Version 7 and under, were used to move through a figure's hierarchy.  If the right shoulder were selected the down arrow is supposed to select the figures right forearm, the up area moves the selection to the figure's right collar.

Not sure this always works though and don't really know why.

I usually use the dials to translate/rotate and the drop down menus on the Parameter Dials menu to select body parts.  If the scene is not too complicated using the mouse sometimes to select body parts.