:biggrin:

I would'nt expect bones to be in order here either.

"...to add a little jiggle to your figure..."*

Magnets are what you would use to create unique deformations on your figures surface.

" I'd like to make these figures as resource light as possible, to make them suitable for animation."

It would then be commonplace to convert you magnets into morphs, with the Spawn feature.  Morphs can also me spawned/combined/slimmed into less morphs; as morphs can get heavy also, especially when not in use(set to 0)  I have a V3.PZ3 where I archive all of my morphs and magnets.  As is it is 250MBs.  But, for rendering, I've use a 10MB.PZ3; that looks exactly like the 250MB, just with it's magnets/morphs consolidated into 1 morph per part.

shehzad105 - Magnets. 

Here is a quick Magnet tutorial:

1.)  Make sure you have the Part of the Figure that you want to deform selected, and click Object > Create Magnet.

2.)  The 3 parts to the new Magnet Set are now listed in the Props list for the Figure or Prop; they are the Magnet, the Magnet Zone, an the Magnet Base.

3.)  Select the Magnet Zone.

4.)  Goto Display > Element Style > Wireframe.  This is the really hard part, that Poser's Default is way off base by, though nobody ever tells!

5.)  Now open the Parameters Palette.

6.)  Move the wireframe to intersect with the area you want to Deform.

7.)  Select the Magnet part of the Magnet Set.

8.)  As you alter the Parameters of the Magnet(away from the Base)  the geometry within the Zone will likewise be effected.