That's such a cool idea!
As long as you're doing an official Serenity screening for Equality Now, anything else you've got planned fits in very well as Affiliate-style events. Just remember that at least 75% of the total proceeds from your events needs to go to Equality Now to be part of CSTS. For the fan-films who are seeking to support their own charity, you'll need to work out how to structure the events so that Equality Now still gets 75% of the total amount raised from all of your events (that could be 100% from your main event and then 25% from the other films?)
It sounds like you're going to have a really great year!!