TIG and Dave -- Thanks for answering. Both your comments raise some side questions.
TIG: I think I probably should have used the term "Lock", although it, too, has meaning elsewhere in Sketchup. The distortion/movement experience by the un-componentized collection of lines/faces (forming the cube and rectangle) is different from the the stickyness.
Maybe the way to describe what I was after is a un-enabled future feature, that is, one which will move the face of a component (and stretching adjacent lines) ((and stretching, with those lines, the faces bounded by those lines)), if it is "LOCKED" to an adjacent surface which moves.
Dave: What I think I read into your words: The stretching that would occur with Dynamic Components would also distort by the same factor the joinery at the To-Be-Moved ends. Is that right ?
Dave & TIG (or anyone else...):
Would it be fair to say that the best mechanism for the simple side wall slide-to-the-side, is to
a. move the side wall component
b. grab each shelf (or an instance) by an end-point un-joined (that is, not by cut-back, joined bits at the end), and
c. stretch the shelf till it sits in the corresponding joinery (eg, Dado) on the side wall
?
This maneuver becomes even more painful, and this is really the reason for this question, when my model morphs from
cube/rectangle ---> simple shelf ---> a cabinet with inset drawers, doors or other parts (ie, a cabinet....) ---> a collection of variants of cabinets for a wall system
In the last case, --everything-- has to be adjusted for width, if I merely "stretch" the whole thing wider.
The same problem comes up if I craft a living space (a house, say), and move a internal or exterior wall. If I don't use components, things might move/slide easier. If I use components for their obvious advantages, I lose the "editability of the whole"
Is my thinking landing in the right place?