> 1) At some future point, when I wish to run HTTrack with
> Action "Update existing download", how do I cause HTTrack
> *NOT* to delete previously acquired

"Do not purge old files"

> 2) In another case, I am only interested in image files 
over
> a certain size (fullsize, no thumbnails).  Is it possible 
to
> program HTTrack to acquire such files and ignore all else 
as
> it spiders through the site?
To exclude GIF files smaller than 100KB:
-*.gif*[<100]

and the same for JPG files:
-*.jpg*[<100]

(warning: this will cause many broken images for "small" 
files)

> 3) In another instance, I am only interested in image 
files
> which have a certain keyword somewhere in the pathname 
(not
> in the filename).  Is it possible to program HTTrack to
> acquire only image files that meet that condition?
-*.gif +*keyword*/*.gif
-*.jpg +*keyword*/*.jpg
and so on..