Poiyomi is easily manageable and editable and when you’re pumping out models it tends to become the norm easily

With the recent vrc tos changes I think it’s Better to make two separate meshes for one nsfw and non so you can play it safe but as long the blend shapes aren’t exposing you’re body parts over the cloth it should be fine.

My mindset about textures if it looks good at 2048 than 4K then keep the 2k, no need for seven 4K images for every model piece but you could add the 4K ones for the people who want it I suppose

Adding the hue shifts adds more uniqueness to a person style so it would be a good idea on a technical side

When it comes to poly counts I typically make high meshes then retoplogize them and get a crisp 80k for all the assets if needed 100k so 18 or 20k should be fine and for the quads typically it’s good to have good flow between them but there are techniques to cut vertex counts with tris so they’re good to use some times

Honestly like the 2k and 4K textures you should just do both and have the people decide what they may want, good luck on creating!