Is there a way to turn on some “save everything visited” switch and then, until its turned off, save everything visited into DevonThink-both HTML, links and images. Preferably automatically.
Unfortunately not. One could, of course, write a watch dog script that observes what you do in the front-most Safari window and acts on it.
Seems Trillium wants to “save everything visited” in DA, not Safari, to DT.
In this case, too, a script seems to be the way to go as this function is not yet built-in (and unlikely to get added).