I just finished reading this entire thread and I must say thank you to all the people who posted these spoiler for I have been greatly spoiled indeed.
Well given what I've read so fare I know this much...
Shana 0: Takes place in Shana's earlier days as a Flame Haze and had no chose but to pretend to be some guys girlfriend while she hunted some bad guys.
Shana S: Appears to be a type of Episodic Narrative which is a collection of short stories on different characters in the series.
Shana 1 - 9: Had been covered in Shana season 1 with a few changes for the sake of time and maintaining their budget.
Shana 10 - ?: Will be animated for season 2 and whatever else after that maybe left over for a season 3 if they get that a fare.
Also Novel 16 Hit me hard...