Well, let's see how far we can get. Maybe we can get a pointer now and then if we're actually stuck.
Yeah, indicating particular images (one or more) (or directories) as info passed to a script is important (right-click, keyboard shortcut, menu, toolbar, or whatever), we'll certainly want that in the long run.
I'm kind of guessing that the work for a good clean interface for that stuff is only partly done, or something (and as you say has been taking a lower priority than other things; there's a LOT of stuff that would be desirable to do, I'm not sure how I'd prioritize it myself if I had the full list in front of me. And there's a rumor that not everybody completely agrees with me on what's important :-).
I had a bunch of Perl scripts (still have them) for moving stuff from TP to my web gallery, and replacing images when I updated them and such, that I could run from the toolbars. Worst case, maybe we can hook things up that way temporarily.
We'll see how much time I have, might have time and energy to get somewhere on this for a few weeks now.