Look for an agent. Companies normally don't take unsolicited scripts, so you will need to get an agent to represent yours.
You should not write a screenplay like you would write a novel, or an essay, or newspaper column or any other writing. A screenplay follows a rigorous format and tells a story.
You can do anything you like after you write a screenplay.
Write a screenplay.... Then shop it....
Yes Melissa did write the screenplay for Twilight:D
A screenplay is a product. It tells a story. You can write the story as a pitch, as a treatment, as a novel or as a screenplay. Both are required in order to tell your story on film.
You do indeed need permission to write an adapted screenplay. This is to make sure you are following the copy rights.
It will depend on the writer as to how long it takes to write a screenplay for animation. It could take several weeks to even years.
It shouldn't be capitalized in a screenplay unless it was in the title.
Your best bet is to write your screenplay and then write a query letter to the show's producers. Tell them what your screenplay is about - and let them know you've actually finiished writing it - and see what they think.
If you've written a screenplay, an agent can help you sell it. Selling it yourself may or may not be your strong suit.
Yes
George A. Romero wrote the screenplay but King previously published the stories as short stories.