Hmm, yea, you are right...I just got really in touch with the UI Editor and noticed, that you can save all your changes into your own UI Set and switch around at any time. Then I can keep it, so that it only runs with the default ui, which won't be a problem. Actually, I noticed, that the windows remain at the same position for the other 2 pre-defined presets from the UI Editor, which are Retro and Extended Quickbars. That's...nice. Support for UIs with moved frames will not exist (yet?) tho.
A Buy/Restock and Use feature for Companion Gifts, you say...should be possible.
Then I can only say: There's a Prototype already for 1.2.0a, which uses NO! mouse movement (only hidden mouse clicks) and can even run in background mode (partly so far, still need to check some stuff), which might be the most interesting feature for players.