Hello! Thanks for the reply!
It actually wasn't hard to find the folder; I just went to the root directory in Windows Explorer and did a search for Impart, and removed the Impart directory that still had files in it after an uninstall.
Yeah, these design choices can be trickier than they seem on the surface. In particular, with the issue of distinguishing between tags highlighted as part of a filter, and tags highlighted to signify they are tied to the selected file; the way I'd do that is have two separate types of highlight. Maybe highlight the border for selected items, and highlight the whole thing for filters?
As for selecting multiple items, either of your ideas would work depending on what the user is trying to do. It might be most useful to have a toggle in the side-bar for which behavior to use. Though If you want to go for something simpler to implement in the interim, you could set it up so that it only auto-highlights when a single image is selected, then unhighlights as soon as any additional items are selected at the same time.