When a frustrated screen writer loses his voice, he must learn to write his way to mental freedom, but when a over opinionated logliner steals his idea he has only 200 hours before his spec is sold, and must submit his script and save his soul.

A character writing something as their major action is not a very cinematic or visual thing to do. Maybe this could work as a book?

You've included two catalysts; losing his voice (I take this to mean a literally silencing of the character, as opposed to him losing his unique voice as a writer) and someone stealing his idea. I think someone stealing his idea is more compelling, but whichever you're more keen on, whittle it down to just the single "event" that sets your story into motion.

What does "write his way to mental freedom" look like? If I was the producer trying to decide whether to buy your script or not, would I be looking at some soaring epic or a single actor in a single room?

How does the script submission save his soul? Is there some sort of link between finishing and selling this script and him receiving his voice back?

Why 200 hours? What happens then?

I love the idea However, what is this going to be. Just writing the script? How will he submit his script. Does he have to go around and get ideas?

I'm not sure how this would work but I like it a lot