BP Jonsson wrote:
>
> - People usually have one language or dialect which was
>    there first in real time, and which often remains central
>    to the whole edifice, from which various imaginary
>    ancestors, daughters and siblings (what I call "stages" or
>    "nodes") radiate.

The two languages I've worked on the most, Kash and Gwr, are direct 
opposites in this respect. Kash was developed a priori as a "present-day" 
language whose history, such as it is, existed only in my mind; and later on 
several sheets of paper. I just haven't done anything further with that 
aspect.

Gwr OTOH started in the same way, but I quickly realized that I couldn't 
just create monosyllables + tones out of thin air-- there had to be some 
kind of logic and organization behind it. That led to the creation of Proto 
Baw Da Gwr and the sound changes (and discarding a good bit of early vocab 
that turned out to be impossible according to the rules). PBD however is but 
one node on a family tree (say Latin maybe, as opposed to PIE), and I don't 
know what the other/earlier nodes really look like-- except they will be 
more complex.
>
>    - It is not necessarily or usually the case that what I
>      call a later version of one language represents a break
>      or fresh start relative to any or all earlier versions.
>      A new version need not be a rewrite, but probably a
>      conscious revision as opposed to a tweak or a bug fix.
>      :-) Changes and differences may be gradual, cumulative,
>      abrupt or whatever.

I've not done that; a lot of early Kash vocab simply got lost/mislaid; the 
phonology however has stayed remarkably stable, about the only change has 
been to disallow true diphthongs. Revisions to old Gwr vocab would be 
considered abrupt, I think.
>
>    - "Stages" may go through various "versions" or
>      "revisions", often without all the stages being
>      revised at the same time, although a revision in some
>      place in the family tree -- especially a major one --
>      may of course have larger or smaller repercussions
>      throughout the tree.

This may happen in Gwr if I ever come up with the PIE-analog, but I'll be 
more inclined to force the proto to agree with the modern.
>
> -    Unlike real language history the protolanguage is a
>           secondary product made to fit its daughters.

That will definitely be the case with Kash.
>
>    - Should I use the term "node", as on an imaginary family
>      tree,

Yes, that's conventional. A node can be viewed as a subordinate 
proto-language.

throughout instead of "stage". What do native
>      English speakers think of these terms (stage, node,
>      version) as I use them?

I'd call "stage" a period or point in time in the development of a given 
language-- "Middle English", "Early Modern Engl."; node, see above; version 
might refer more to dialects.