Hi @Max ,
thank you for your questions. It is an answer to your 3rd question.
For me a faceswap app is a big deal.
It’s about imagining your own face with different hairstyles.
It’s the same face on everyone. I have generate with AI
To your 1st question.
I think you could also base it on the photo gallery. I offer ready-made photos and the user replaces the one they want with their own photo and the AI swap the face. Thats it. 
The left photo is a original …its a selfie (but its not me 
), and the photo right site is AI generatet with the desired hairstyle
The solutions are already available from other providers, but they are very expensive to integrate into your own website. Maybe elfsight is interested in something like that. Of course that would be great.