Watercolors?

Would watercolor pencils be ok to do a Dollfie Dream face with? Would they damage the vinyl? Would they not react well to sealant? I don't have great fine motor skills, and I don't feel comfortable using liquid paint to give my doll a faceup. Are watercolor pencils, or heck, even regular colored pencils a viable option?

Watercolor pencils, absolutely! Regular colored pencils, no. (No wax- or oil-based pencils/products)
I only work with watercolor pencils and soft pastels - it's just easier than "liquid paint". The issue is that the pencils may scrape the sealant, especially since you tend to need the pencils to be sharp. So add multiple layers of sealant, and try to work in layers (as in start with faint lines and make the color stronger as you go).

I use watercolor pencils to sketch the shapes of a face up before adding a paint layer on top, and I've never had any troubles with them. I would just make sure to coat the doll in a few layers of sealant before applying any pencils, since the darker colors could pose a stain risk.