KingLeer, since your the director ill ask you, What rights do I have to use in-game footage that I capture in a film that I make? Does it change when its for profit or non profit? And how should I go about accrediting game personnel in the credits if in-game footage is used?
Not the director, but I am familiar with entertainment law.
You're entering what is still considered a grey area by posting a movie using in-game content; however, historically speaking, highly transformative, non-for-profit works have been largely left alone, as they generally are not considered detrimental in any way to the original work.
You wouldn't be able to produce a commercial video for the same reason MWLL cannot produce this as a commercial game: You'd be using intellectual property that didn't belong to you. There are exceptions to this (such as parodies that critique the original work), but generally speaking, that would be inviting a takedown from Microsoft.
As for giving credit... That is up to you. Legally, it isn't required (but usually advised).
NOTE: Bill S. 978 - http://www.govtrack.us/congress/billtext.xpd?bill=s112-978
necessitate getting permission from Microsoft to do the video. To be honest, I'm not exactly sure how that would work. A lawyer (or a bigger law junkie) would know more.
Finally, when in doubt, follow the four factors of fair use:http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter9/9-b.html
EDIT: Oops! If it isn't obvious, I should clarify that I'm referencing US copyright laws. If you're not American, you'll want to understand how these laws could potentially translate to you via the Berne Convention and the Universal Copyright Convention, as your biggest concern would be Microsoft.