Some of your questions aren't really ALiVE-specific which is why they are not in the FAQ. For working in the editor and with PBO files see this tutorial:
http://warmod.webs.com/importmissiontoeditor.htm
With regards to ALiVE saving and persistence please see this link:
http://alivemod.com/wiki/index.php/ALiVE_Data
Your server will need to run the @aliveserver mod in addition to @alive and @cba_a3. Do not run @aliveserver mod on your client.
You will need a War Room account - once you sign up there are instructions there on setting up your server to work with saving/persistence.