Q. The citation style I need to use is not listed in Zotero, can I add others?

There are over 6000 citation styles that can be added to Zotero.

Go to the "gear" icon in the Zotero menu bar and select Preferences-> Cite --> Styles tab. 

There is a link at the bottom to "Get additional styles..."  You will open a web page where you can search for and install additional styles.