You're done already I think so this info is not very timely I appreciate, but I'll give my 2 cents worth on the topic.
My interior was black originally but well faded and scratched. I used the Fade Away product from "Just Dashes"
http://www.justdashes.com/FadeAwayArticle.htmAs someone says cleaning is key. Put 10 times the effort to the prep than to the painting time. Clean and clean again. Any gresase or dust shows and makes the paint not stick well. This approach and this product worked well for me but you have to be careful not to scratch the hard surfaces after because it goes down to the original surface quickly. I bought mostly all new soft interior (seats, dash) but painted all the hard surfaces (door panels, kick panels, quarter plastic, etc) and the sun visors.
Here's the visors:
I would be careful sanding plastic because you can sand off the texture. It's like when people work on fibergalss bodied cars, wanting to do repairs to cracks, etc. Fiberglass (like plastic and unlike metal) sands down. I've seen people trying to repair a crack in a fibergalss body and end up carving a dip or trench in the body where the crack was.
I hope your work turned out good for you. As long as you are satisfied with it that's all that matters. It looks good to me from your photos.