At the moment when you don’t know what these components do you have to either ask the community or try all of them to find out. My suggestion is to add little animations to the webpage that show what each of them is doing so everyone can find the perfect solution much faster. In case of Slider there could be the JUCE default knob being dragged a bit for example. A lot of these are not very self-explanatory, like HWNDComponent, PropertyComponent, ConcertinaPanel etc.
I wonder how you would animate these?
well, tell me about one of them and i try to come up with something. i just feel like there’s almost always a graphical way to demonstrate what a graphical structure is doing.
Well, just remove HWNDComponent from your list, that is nothing you would need very often (I guess mostly for hosting plugin editors).
I agree a screenshot per component would not hurt.
The best reference is probably the DemoRunner, where you can see many (most?) Components in action.