Can I use this script to win some screen writing contests then use that success to sell other scripts I wrote? but not the one that already won? Will buyers only want the winner script or as long as you've won a contest they won't care about which script you want to give them?
Winning some screen writing contests can boost your recognition
to agents and producers.
Buyers want the script that best suits their needs. A producer
may not want the winning script for many different reasons but
may want a script from you.
That's why we are all saying that having several scripts is a good
thing.
I disagree with indietalk's example; if you're a baker with a kick-ass
cookie recipe but you don't want anyone else making those cookies
it might be a good idea to come up with a different (also kick-ass)
cookie recipe to sell to others. Get your name out there, show your
recipes are liked by others then make those first cookies yourself.
pedramyz, since you want not only to direct but you want full creative
control and final cut all paid for by an American producer one way to
earn that very rare place in American film making is to show how
valuable you are. A few screenplay sales can help. A few short films
and a low budget feature as writer/director can help.
There isn't one path. Perhaps your current script will be seen by an
American producer who wants it bad enough to bring you to the U.S.,
hire you to direct and give you final cut. If you don't show the script
you can not get that opportunity.