The OP hasn't come back in two months time, but I will say for anyone wondering in the future if SFO is safe, it is in my experience. I consider SFO airport one of my homes away from home.
I have slept airside and landside mostly Terminal 3 because I was predominantly a UA flyer in my mileage-running heyday. The food court booths, including landside T3 where Subway is, and landside international terminal, are great.
Airside and in baggage claim, there are these weird pieces of furniture I cannot even begin to describe, so I'll post a photo. There are also the old loveseat-sized couches, for sure in T3 in front of Buena Vista Cafe near gate 82, and in front of Amoura Cafe near intl G Terminal gate A3. I'll look for a pic of those.
There are always other awake and sleeping travelers around, cleaning crew, and the airport SF police officers on their segways.