Just a quick tidbit and then I'll update more tomorrow.
After two weeks of lame/slow customer service emails from airbnb, today something new happened. My younger sister who is connected in the music industry began tweeting about airbnb's poor customer service, and referencing both my situation as well as their previous bad PR stories. After about 20 minutes of continuous tweets, they contacted my sister via twitter. She continued to tweet for an hour, then I magically received a phone call from an airbnb Supervising Case Manager. This was the first staff member I spoke with who actually knew about CA evictions and the law here (their customer service dept seems to be based in southern Oregon, so the previous manager I spoke with didn't know much, and simply told me to call the police to remove them.)
Long story short--previous posters are right, the only way to get customer service out of airbnb is to publicize the situation. It is sooooo unfortunate that this is the case. But that is how it is with this company.
The resolution that was proposed to me by the airbnb supervisor--she would contact ( or attempt to contact) the squatter, offer to have airbnb move them into a hotel at no charge for 30 days. Unfortunatly I have not heard back this evening, so I assume the squatter will be ignoring that offer, especially if he knows he can ride it out in my place for longer than 30 days. For shame!
I will continue to update. This has been one very stressful day, however I am so grateful for all of the comments, advise, feedback and support that has come my way on this site. Thank you all for taking the time to share. I really appreciate it.