This is the first time I talk to you, because I found almost anything answered in this forum.
Now I've got some questions...
But I will keep it simple:

1. VSTi with an audio loop player and no sampler with embedded sounds
   but "library" folder for audiofiles and userpresets at user specified location?
   I would like to use my regular "library" folder on external SSD where all of my VST libraries are.

2. Seperate folder for convolution wav files?

3. Why no custom settings option to simply select a library path?
   A installer could predefine the library path. But users shouldn't need the installer for selecting it.
   (Maybe I know why there is no option. It just would be nice to have it there.)

4. Are those audiofiles and userpresets in appdata folders
   because they are streamed and temporary or something?

After saving a preset, it does remember the audiofiles - no matter where they are stored.
What a powerful function.

5. Should I be careful with making a VSTi where users can make their own libraries?
   Or is this more critical if they can share presets with no royalty free sounds, no recorded sounds etc?
   Am I responsible for this or can I say the users are responsible for what they are doing with the VSTi?

6. With right click on the loop player it opens the appdata folder.
   The audio waveform is titled {PROJECT_FOLDER}"title".wav
   I guess there must be a way for editing the location. Am I right?

(You might use only impulse responses and stuff as audiofiles.
Using embedded files is no option in this case.)

Maybe you can tell me how to achieve this?! ;)