I hope to add keywords to the Finder part of the app in the future. I need to figure out a few things first.
I cannot support keywords in Photos, even though Mac Photos lets you add them. That’s because Apple does not allow apps on the Mac App Store (yes, that’s right) to read or write keywords.
In general, I try to avoid implementing features on only one “half” of the app because it’s very confusing to people (especially when keywords are available inside the Photos app).
As far as Perspective goes, I suggest trying the vertical and horizontal sliders – that is an easy way to correct perspective.