Superstar -
Check out the AACCA website for more information on college rules...here is the link:
http://aacca.org/content.aspx?item=Safety/Test.xmlThe difference between surfaces is what is going to drive the answers to some of your questions.
A double based extension can be performed without a backspot on both the court or matted surface. The surface that you are on determines how you can enter or dismount a stunt. No released twists on the hardwood.
Rules are the same for coed and all-girl collegiate teams. No distinction between the two is made.
As for libs...

...if you've got a guy...there is no need to do the stunt double based.
